# GCN_circulars

GRB_name: GRB151231A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18787
SUBJECT: GRB 151231A: Fermi GBM observation
DATE:    15/12/31 18:46:25 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH), C Meegan (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 10:37:47.52 UT on 31 December 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 151231A (trigger 473251071 / 151231443).

The on-ground calculated location, using the GBM trigger
data, is RA = 65.6, DEC = -61.5 (J2000 degrees,
equivalent to 04 h 23 m, -61 d 32 '), with an uncertainty
of 1 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 157 degrees.

The GBM light curve shows two well separated peaks
with a duration (T90) of about 71 s (50-300 keV).
The time-averaged spectrum from T0-2.3 s to T0+85 s is
best fit by a Band function with Epeak = 198 +/- 7 keV,
alpha = -1.00 +/- 0.04, and beta = -2.61 +/- 0.09

The event fluence (10-1000 keV) in this time interval is
(9.7 +/- 0.1)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+5.3 s in the 10-1000 keV band
is 46.9 +/- 1.5 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB151231B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18788
SUBJECT: GRB 151231B: Fermi GBM observation
DATE:    15/12/31 19:42:06 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH) and C Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 13:38:08.17 UT on 31 December 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 151231B (trigger 473261892 / 151231568).


The on-ground calculated location, using the GBM trigger
data, is RA = 150.1, DEC = 28.8 (J2000 degrees,
equivalent to 10 h 0 m, 28 d 49 '), with an uncertainty
of 3.1 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 0.8 s (50-300 keV).
The time-averaged spectrum from T0-0.3 s to T0+0.4 s is
abest fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.65 +/- 0.10 and
the cutoff energy, parameterized as Epeak, is 419 +/- 58 keV.

The event fluence (10-1000 keV) in this time interval is
(1.20 +/- 0.07)E-6 erg/cm^2. The 64 ms peak photon flux measured
starting from T0 in the 10-1000 keV band is 14.8 +/- 1.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB151227B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18792
SUBJECT: GRB 151227B: CALET Gamma-Ray Burst Monitor detection
DATE:    15/12/31 22:37:10 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

K. Senuma, A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 151227B (Toelge et al. GCN Circ. 18727; Hurley et al. GCN Circ. 18773; 
Golenetskii et al. GCN Circ. 18781) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 
5:13:49.89 UT on 27 December 2015.  The clear burst signal was detected by HXM1 and SGM 
instruments.  

The light curve of the SGM shows three main peaks.  The first peak starts at T0, 
peaks at T0+2 sec and ends at T0+4 sec.  The brightest second peak, which consists 
of various sub-peaks, starts at T0+20 sec, peaks at T0+31 sec and ends at T0+40 sec.  
The third peak starts at T0+40 sec, peaks at T0+45 sec and ends at T0+50 sec.  
The T90 duration measured by the SGM data is 42.0 +- 0.3 sec (40-1000 keV).  

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.  


GRB_name: GRB160101A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18793
SUBJECT: GRB 160101A: MAXI/GSC detection
DATE:    16/01/01 02:40:46 GMT
FROM:    H. Negoro at Nihon U.  <negoro@phys.cst.nihon-u.ac.jp>

D. Itoh (Miyazaki U.), H. Negoro (Nihon U.), 
H. Tomida,  S. Nakahira, M. Ishikawa, Y. E. Nakagawa (JAXA), 
T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), 
N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), 
A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), 
H. Tsunemi, R.Imatani (Osaka U.), 
M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.), 
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), 
Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.), 
M. Yamauchi, K. Furuya (Miyazaki U.), 
K. Yamaoka (Nagoya U.), M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient 
source at 00:43:52 UT on 2016 January 1.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (219.733 deg, -13.823 deg) = (14 38 55, -13 49 22) (J2000) 
with a statistical 90% C.L. elliptical error region 
with long and short radii of 0.10 deg and 0.09 deg, respectively. 
The roll angle of long axis from the north direction is 150.0 deg counterclockwise. 
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 1543 +- 100 mCrab (4-10keV, 1 sigma error).

Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (219.635 deg, -14.100 deg) = (14 38 32, -14 05 59) (J2000)
(R.A., Dec) = (219.486 deg, -13.957 deg) = (14 37 56, -13 57 24) (J2000)
(R.A., Dec) = (220.532 deg, -12.732 deg) = (14 42 07, -12 43 54) (J2000)
(R.A., Dec) = (220.677 deg, -12.878 deg) = (14 42 42, -12 52 39) (J2000)
There was no significant excess flux in the previous transit at 23:11 UT on 2015 December 31
with an upper limit of 20 mCrab for each.


GRB_name: GRB160101A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18794
SUBJECT: GRB 160101A: Tiled Swift observations
DATE:    16/01/01 04:32:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 160101A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00051

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160101A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18795
SUBJECT: GRB 160101A: Swift-XRT afterglow detection
DATE:    16/01/01 15:30:06 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

L. Izzo (URoma/ICRA), V. D'Elia (ASDC), P. D'Avanzo (INAF-OAB), T.G.R.
Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), A.P. Beardmore
(U. Leicester), S.L. Gibson (U. Leicester), A. D'Ai (INAF-IASFPA) and
P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 160101A (Itoh et al. GCN Circ. 18793) in a series of
observations tiled on the sky. The total exposure time is 1.7 ks,
distributed over 7 tiles; the maximum exposure at a single sky location
was 512 s. The data were collected between T0+13.2 ks and T0+19.6 ks,
and are entirely in Photon Counting (PC) mode. 

An uncatalogued X-ray source is detected and is above the RASS limit,
and is therefore likely the GRB afterglow.  The position of this source
is RA, Dec=219.6506, -13.8154 which is equivalent to:

RA (J2000): 14:38:36.14
Dec(J2000): -13:48:55.5

with an uncertainty of 3.7 arcsec (radius, 90% confidence).  This
position is 4.8 arcmin from the MAXI position. The source has a mean
count rate of 3.9e-01 ct/sec; we cannot determine at the present time
whether it is fading.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.5 (+0.5, -0.3). The
best-fitting absorption column is  1.20 (+2.17, -0.29) x 10^21 cm^-2,
consistent with the Galactic value of 9.1 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.6 x 10^-11 (5.1 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.20 (+2.17, -0.29) x 10^21 cm^-2
Galactic foreground: 9.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.5 (+0.5, -0.3)

The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/xrt_products/TILED_GRB00051/index_1.php.
The results of the full analysis of the tiled XRT observations are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00051.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160101A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18796
SUBJECT: GRB 160101A: Fermi GBM observation
DATE:    16/01/01 15:45:16 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH) reports on behalf of the Fermi GBM Team:

"At 00:43:53.61 UT on 01 January 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160101A (trigger 473301837 / 160101030)
which was also detected by MAXI/GSC (Itoh et al., GCN 18793)
and Swift/XRT (Izzo et al., GCN 18795).
The GBM on-ground location is consistent with the MAXI and Swift positions.

The angle from the Fermi LAT boresight at the GBM trigger time is 93 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 4.7 s (50-300 keV).
The time-averaged spectrum from T0 to T0+7.3 s is
best fit by a Band function with Epeak = 135.0 +/- 5.2 keV,
alpha = -0.78 +/- 0.03, and beta = -2.26 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(1.682 +/- 0.024)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.9 s in the 10-1000 keV band
is 35.7 +/- 0.9 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160101A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18797
SUBJECT: GRB 160101A: Swift/UVOT Detection
DATE:    16/01/01 15:52:34 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began tiled observations of the field of the MAXI-detected
burst GRB 160101A (Itoh et al. GCN Circ. 18793) 13.2 ks after the burst.  A
fading optical source consistent with position of the XRT source reported by
Izzo et al. (GCN Circ. 18795) is detected in the initial UVOT exposures in
the u filter.

The preliminary UVOT position is:
     RA  (J2000) =  14:38:36.12 = 219.65051 (deg.)
     Dec (J2000) = -13:48:55.4  = -13.81539 (deg.)
with an estimated uncertainty of 0.58 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT 
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for 
the early exposures are:

Filter     T_start(s)   T_stop(s)   Exp(s)       Mag
u           13195        13397       198     17.55+-0.10
u           19592        19652        59     18.32+-0.32

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.09 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB160101B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18798
SUBJECT: GRB 160101B: Fermi GBM detection
DATE:    16/01/01 17:41:29 GMT
FROM:    Adam Goldstein at Fermi-GBM/UAH  <adam.m.goldstein@msfc.nasa.gov>

P Veres (UAH) and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team:

"At 05:10:12.86 UT on 01 January 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160101B (trigger 473317816 / 160101215).

The on-ground calculated location, using the GBM trigger
data, is RA = 1.4, DEC = 55.2 (J2000 degrees,
equivalent to 0 h 5 m, 55 d 14 '), with an uncertainty
of 1.4 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 9 degrees.


The GBM light curve consists of a single pulse
with a duration (T90) of about 6.9 s (50-300 keV).
The time-averaged spectrum from T0-0.5 s to T0+6.7 s is
adequately  fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.33 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 952 +/- 468 keV.

The event fluence (10-1000 keV) in this time interval is
(2.73 +/- 0.14)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.3 s in the 10-1000 keV band
is 2.1 +/- 0.2 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160101B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18799
SUBJECT: GRB 160101B: Fermi-LAT detection 
DATE:    16/01/01 17:43:46 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin@nasa.gov>

J. L. Racusin (NASA/GSFC), S. Razzaque (UJ, South Africa), and M. Axelsson (KTH, Sweden) report on behalf 
of the Fermi-LAT team: 

At 05:10:11 UT on January 1, 2016, Fermi-LAT detected high-energy emission from GRB 160101B, which was 
also detected by Fermi-GBM (trigger 473317815/160101215). 

The GBM location was initially inside the LAT field of view at an angle of 9 degrees to the LAT boresight, and 
remained in the LAT field of view until ~T0+1500 s. No significant excess is seen using standard >100 MeV 
likelihood analysis procedures. 

Using the LAT Low Energy (LLE) data selection, over 100 counts above background were detected within a 10 s 
interval coinciding with the time of the GBM emission. This data selection has insufficient spatial resolution to 
provide a reliable LAT localization. Since an excess of events were not seen using the standard analysis 
selection, this detection is likely due to low energy gamma-rays (below 100 MeV). 

The Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov). 

The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 
300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many 
scientific institutions across France, Italy, Japan and Sweden.

 


GRB_name: GRB160102A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18801
SUBJECT: GRB 160102A: MAXI/GSC detection
DATE:    16/01/02 04:49:22 GMT
FROM:    H. Negoro at Nihon U.  <negoro@phys.cst.nihon-u.ac.jp>

D. Itoh (Miyazaki U.), S. Nakahira (JAXA), H. Negoro (Nihon U.), 
H. Tomida, M. Ishikawa, Y. E. Nakagawa (JAXA), 
T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), 
N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), 
A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), 
H. Tsunemi, R.Imatani (Osaka U.), 
M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.), 
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), 
Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.), 
M. Yamauchi, K. Furuya (Miyazaki U.), 
K. Yamaoka (Nagoya U.), M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient
source at 03:39:16 UT on 2016 January 2.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (80.840 deg, -21.041 deg) = (05 23 21, -21 02 27) (J2000) 
with a statistical 90% C.L. elliptical error region and
with long and short radii of 0.19 deg and 0.14 deg, respectively. 
The roll angle of long axis from the north direction is 180.0 deg 
counterclockwise. Theres an additional systematic uncertainty of 0.1 deg 
(90% containment radius).
The X-ray flux averaged over the scan was 265 +- 32 mCrab
(4-10keV, 1 sigma error).

Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(80.157 deg, -20.852 deg) = (05 20 37, -20 51 07) (J2000)
(80.155 deg, -21.225 deg) = (05 20 37, -21 13 28) (J2000)
(81.765 deg, -21.221 deg) = (05 27 03, -21 13 16) (J2000)
(81.756 deg, -20.849 deg) = (05 27 01, -20 50 55) (J2000)

There was no significant excess flux in the previous transit at UT 02:06
with an upper limit of 20 mCrab for each.

For more information on this burst:
http://www.maxi.riken.jp/alert/novae/7389136382/7389136382.htm


GRB_name: GRB160102A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18802
SUBJECT: GRB 160102A: Tiled Swift observations
DATE:    16/01/02 06:41:16 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 160102A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00052

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160101A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18805
SUBJECT: GRB 160101A: MITSuME Akeno optical upper limits
DATE:    16/01/02 17:14:36 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

T.Fujiwara, Y.Saito,T.Yoshii, Y.Tachibana, Y.Yano, 
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 160101A (D.Itoh et al., GCN Circular #18793) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-01-01 18:33:56 UT (~17.8 h after the burst). We cound not detect any optical point source in the error circle of the previously reported afterglow detected by Swift-XRT (L.Izzo et al., GCN Circular #18795) in all three bands.

Three sigma upper limits are listed below.

T0+[hour]      MID-UT      T-EXP[sec]         g'           Rc           Ic
---------------------------------------------------------------------------------------
 18.9839      20:18:08          780            > 18.5     > 18.2     > 17.4
---------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration


GRB_name: GRB160102A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18808
SUBJECT: GRB 160102A: Swift-XRT observations
DATE:    16/01/02 20:27:05 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. D'Elia (ASDC), L. Izzo (URoma/ICRA), L.M. McCauley (PSU), J.A.
Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester),
J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Maselli 
(INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 160102A (Itoh et al. GCN Circ. 18801) in a series of
observations tiled on the sky. The total exposure time is 1.8 ks,
distributed over 7 tiles; the maximum exposure at a single sky location
was 597 s. The data were collected between T0+10.8 ks and T0+17.0 ks,
and are entirely in Photon Counting (PC) mode. 

No X-ray sources have been detected. The 3-sigma upper limit in the
field (not including the regions where the tiles overlap) ranges from
~0.03 to ~0.07 ct s^-1, corresponding to a 0.3-10 keV observed flux of
1.0e-12 to 2.8e-12 erg cm^-2 s^-1 (assuming a typical GRB spectrum).

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00052.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB151231A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18810
SUBJECT: GRB 151231A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/01/03 08:07:31 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

M. Moriyama, A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, K. Senuma, 
Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 151231A (Veres et al. GCN Circ. 18787) triggered the CALET 
Gamma-Ray Burst Monitor (CGBM) at 10:37:53.15 UT on 31 December 2015.  The 
clear burst signal was detected by all instruments.  

The light curve of the SGM shows two main peaks.  The first peak starts at T0-2 sec, 
peaks at T0 and ends at T0+5 sec.  The second peak starts at T0+50 sec, peaks at 
T0+60 sec and ends at T0+70 sec.  The T90 duration measured by the SGM data is 
66.0 +- 0.7 sec (40-1000 keV).  

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.  


GRB_name: GRB160101A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18814
SUBJECT: GRB 160101A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/01/04 07:54:40 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Yamada, A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, K. Senuma, 
M. Moriyama (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 160101A (Itoh et al. GCN Circ. 18793; Veres et al. GCN Circ. 18796) 
triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 00:43:54.04 UT on 1 January 2016.  
The clear burst signal was detected by all instruments.  

The light curve of the HXM shows a multiple peak structure starting at T0-2 sec and 
ending at T0+8 sec.  The T90 duration measured by the HXM1 data is 
7.2 +- 1.3 sec (7-100 keV).  

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University. 


GRB_name: GRB160104A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18815
SUBJECT: GRB 160104A: Swift detection of a burst
DATE:    16/01/04 11:39:40 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

A. Melandri (INAF-OAB), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
P. D'Avanzo (INAF-OAB), P.A. Evans (U Leicester), C. Gronwall (PSU)
and K. L. Page (U Leicester) report on behalf of the Swift Team:

At 11:24:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160104A (trigger=669319).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 76.804, +11.354 which is 
   RA(J2000) = 05h 07m 13s
   Dec(J2000) = +11d 21' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed multiple weak peaks
with a duration of about 20 sec.  The peak count rate was ~1929 counts/sec 
(15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:25:30.0 UT, 79.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 76.7965,
11.3239 which is equivalent to:
   RA(J2000)  = 05h 07m 11.17s
   Dec(J2000) = +11d 19' 25.9"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 111 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.71
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 85 seconds after the BAT trigger. No credible
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers none of  the XRT error circle. The 8'x8'
region for the list of sources generated  on-board covers 100% of the
XRT error circle. The list of sources is typically  complete to about
18 mag. No correction has been made for the expected  extinction
corresponding to E(B-V) of 0.26. 

Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160104A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18816
SUBJECT: GRB 160104A: LCOGT-FTN afterglow candidate
DATE:    16/01/04 12:28:23 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Dichiara (U. Ferrara, ICRANet), S. 
Kobayashi (LJMU), A. Gomboc (U. Ljubljana) on behalf of a larger 
collaboration report:

The 2-m LCOGT Faulkes Telescope North began observing Swift GRB 160104A 
(Melandri et al. GCN 18815) on January 04, 11:50:08 UT (26 minutes after 
the burst trigger) with SDSS R and I filters. Within the XRT error 
circle we detect an uncatalogued source at the following position:

RA(J2000)=   05:07:11.058
DEC(J2000)= +11:19:25.4

with R~19 mag as calibrated against nearby USNOB-1 stars.


GRB_name: GRB160104A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18817
SUBJECT: GRB 160104A: MITSuME Akeno Optical Observation
DATE:    16/01/04 12:28:39 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

Y.Saito, T.Fujiwara, T. Yoshii, Y. Tano, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160104A (A. Melandri et al., GCN 
Circular #18815) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm 
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-01-04 11:24:56 UT (46 sec after the burst) and 
we detected the optical counterpart in Rc and Ic band.
The measured magnitudes were listed as follows.

We obtained following limits for the magnitudes.

T0+[sec]    MID-UT      T-EXP[sec]         g'              Rc                      Ic
-------------------------------------------------------------------------------------------------------
61            11:25:11             30            > 18.5        17.9 +/- 0.3        16.5 +/- 0.2 
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB160104B
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18818
SUBJECT: GRB 160104B: MAXI/GSC detection
DATE:    16/01/04 12:54:30 GMT
FROM:    H. Negoro at Nihon U.  <negoro@phys.cst.nihon-u.ac.jp>

Y. Kawakubo (AGU), M. Nakajima, H. Negoro (Nihon U.), M. Serino (RIKEN),
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. E. Nakagawa (JAXA),
T. Mihara, M. Sugizaki, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN),
N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech),
A. Yoshida, T. Sakamoto, H. Ohtsuki (AGU),
H. Tsunemi, R. Imatani (Osaka U.),
K. Tanaka, T. Masumitsu (Nihon U.),
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.),
Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.),
M. Yamauchi, D. Itoh, K. Furuya (Miyazaki U.),
K. Yamaoka (Nagoya U.),
M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient 
source at 10:13:03 UT on on 2016 January 4.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (108.879 deg, 54.865 deg) = (07 15 30, +54 51 54) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.32 deg and 0.29 deg, respectively.
The roll angle of long axis from the north direction is 72.0 deg 
counterclockwise. There is an additional systematic uncertainty of 0.1 deg 
(90% containment radius).
The X-ray flux averaged over the scan was 123 +- 24 mCrab
(4-10keV, 1 sigma error).

Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (109.823 deg, 54.028 deg) = (07 19 17, +54 01 40) (J2000)
(R.A., Dec) = (108.777 deg, 53.855 deg) = (07 15 06, +53 51 17) (J2000)
(R.A., Dec) = (107.662 deg, 55.997 deg) = (07 10 38, +55 59 47) (J2000)
(R.A., Dec) = (108.739 deg, 56.218 deg) = (07 14 57, +56 13 04) (J2000)
There was no significant excess flux in the previous transit at UT 08:40 UT 
on 2016 January 4 with an upper limit of 20 mCrab for each.

For more information: http://maxi.riken.jp/alert/novae/7391314067/7391314067.htm


GRB_name: GRB160104A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18819
SUBJECT: GRB 160104A: MITSuME Okayama Ks-band upper-limit
DATE:    16/01/04 14:10:03 GMT
FROM:    Kenshi Yanagisawa at OAO/NAOJ  <yanagi@oao.nao.ac.jp>

K. Yanagisawa, D. Kuroda, Y. Shimizu, H. Izumiura(OAO/NAOJ),
M. Yoshida (Hiroshima), K. Ohta(Kyoto) and N. Kawai(Tokyo Tech.)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 160104A (Melandri et al., GCN 18815)
in Ks-band with a wide-field near infrared imager at Okayama
Astrophysical Observatory (Japan).  The imager has effective
aperture of 0.91 m.

Observations started from 11:46 UT on 4th January, 0.38h after
the BAT trigger, to 12:49 UT. The total exposure of 24.0 min
was successfully obtained.

In our co-add image, we did not find any new point source within
the XRT error circle down to the limiting magnitude of
Ks=16.8 (Vega, S/N=3). The photometric calibration was made
against 2MASS field stars.

T0+[sec]    MID-UT     T-EXP[sec]      Ks
---------------------------------------------------
  +3,235    12:18      1440.0          >16.8
---------------------------------------------------
T0+ : Elapsed time after the burt [sec]
T-EXP: Total Exposure time [sec]


GRB_name: GRB160104A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18820
SUBJECT: GRB 160104A: MASTER  early OT detection 
DATE:    16/01/04 14:18:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.Yurkov, Yu.Sergienko, A.Gabovich, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

O. Gress, K. Ivanov, N.M. Budnev, V.A. Poleshchuk, S.A. Yazev
Irkutsk State University


V. Lipunov, E. Gorbovskoy, N.Tyurina, D. Vlasenko, V.Kornilov, 
P.Balanutsa, A.Kuznetsov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institute

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


report on behalf of the MASTER Team:

MASTER-Amur  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160104A (Melandri et 
al., GCN 18815) 10 sec after notice time and 32 sec after trigger time
at 2016-01-04 11:24:46 UT. On our first (10s exposure)  set we have
found optical transient  with 17.0+/-0.3 unfiltered magnitude at LCOGT-FTN 
and 
MITSuME Akeno position (Guidorzi et al., GCN 18816; Saito et al., GCN 18817)
The 5-sigma upper limit has been about 17.3 mag

MASTER-Tunka robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located near Bykal lake  was pointed to the  GRB160104A 66 sec after 
trigger time at 2016-01-04 11:25:20 UT. On our first (10s exposure)  set 
we have found marginally optical transient  ~17 unfiltered magnitude.
The 5-sigma upper limit has been about 17.2mag

The reduction is continuated.
The message may be cited.


GRB_name: GRB160104A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18821
SUBJECT: GRB 160104A: Enhanced Swift-XRT position
DATE:    16/01/04 16:01:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1777 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 160104A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 76.79604, +11.32393 which is equivalent
to:

RA (J2000): 05h 07m 11.05s
Dec (J2000): +11d 19' 26.2"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18823
SUBJECT: GRB 160104A: Xinglong TNT optical observation
DATE:    16/01/04 16:27:58 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin,   X. F. Wang,  J. Y. Wei,  Y. L. Qiu,  J. S. Deng, 
J. Wang,  X. H. Han, C. Wu, D. Xu on behalf of EAFON report:
 
We  observed  GRB 160104A (Melandri et al. GCN 18815)  with 
Xinglong  0.8-m TNT telescope at 11: 26:01UT, 111 sec after the burst.
 
The optical afterglow (Guidorzi et al., GCN 18816; Saito GCN 18817; 
Yurkov et al., GCN 18820 ) was  detected in our white images.
The brightness of the optical afterglow is about 18.45 mag 
at the mid time  of 121 sec afer the burst,  
calibrated by the USNO B1.0 star (RA=05:07:08  DEC=11:02:02  R2=16.25mag).

The message may be cited.


GRB_name: GRB160104A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18825
SUBJECT: GRB 160104A: MITSuME Okayama upper limits
DATE:    16/01/05 00:07:57 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:

We observed the field of GRB 160104A (Melandri et al., GCNC 18815)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2016-01-04 12:42:48 UT (~1.3 h after
the burst). We could not detect the previously reported afterglow
(Guidorzi et al., GCNC 18816; Saito et al., GCNC 18817)
in all the three bands.

Three sigma upper limits of the OT are listed below.
We used GSC2.3 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc     Ic
-----------------------------------------------------
0.08648    13:28:43    4620.0   >20.4  >20.0  >19.4
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB160104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18826
SUBJECT: GRB 160104A:  GWAC upper limit during prompt emission phase
DATE:    16/01/05 03:05:45 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin,  J. Y. Weiï¼Œ Y. L. Qiu,   E. W. Liang,  X. H. Han,   
Y. Xu,  L. Huang,  Y. G. Yang,  X. M. Meng,  H. B. Cai,  
J. Wang,  C. Wu,  J. S. Deng  and H. L. Li   report:

The field of SWIFT GRB 160104A (Melandri et al. GCN 18815)
was monitored by Mini-GWAC system continuously 
during about 1.5 hrs before and 1 hrs after the burst trigger time.
The exposure time for each frame is 10 sec.

No any new optical counterpart (Guidorzi et al., GCN 18816; 
Saito GCN 18817; Xin et al., GCN 18823)  in single frame 
was detected  down to the 5 sigma upper limit of 12.3 mag 
during our observations, calibrated by  nearby USNO B1.0 R2 mag, 
at the epoch of prompt emission phase.

Combining 5 frames during and after the burst trigger initially with a total 
exposure time of 50 sec gives a 5 sigma upper limit of 12.8 mag.

Mini-GWAC system is located at Xinglong observatory,
National Astronomical Observatories, China,
including 6 mounts and 12 Canon 85/f1.2 cameras.
Each mount is equipped with 2 cameras.
For each camera, the Apogee U9000X CCD was used, which gives
about 400 square degree of FOV. The total field of view of this system
is about 5000 sq.deg.

This message may be cited.


GRB_name: GRB160104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18827
SUBJECT: GRB 160104A:  Mini-GWAC upper limit during prompt emission phase
DATE:    16/01/05 03:09:08 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin,  J. Y. Wei, Y. L. Qiu,  E. W. Liang,  X. H. Han,   
Y. Xu,  L. Huang,  Y. G. Yang,  X. M. Meng,  H. B. Cai,  
J. Wang,  C. Wu,  J. S. Deng  and H. L. Li   report:

The field of SWIFT GRB 160104A (Melandri et al. GCN 18815)
was monitored by Mini-GWAC system continuously 
during about 1.5 hrs before and 1 hrs after the burst trigger time.
The exposure time for each frame is 10 sec.

No any new optical counterpart (Guidorzi et al., GCN 18816; 
Saito GCN 18817; Xin et al., GCN 18823)  in single frame 
was detected  down to the 5 sigma upper limit of 12.3 mag 
during our observations, calibrated by  nearby USNO B1.0 R2 mag, 
at the epoch of prompt emission phase.

Combining 5 frames during and after the burst trigger initially with a total 
exposure time of 50 sec gives a 5 sigma upper limit of 12.8 mag.

Mini-GWAC system is located at Xinglong observatory,
National Astronomical Observatories, China,
including 6 mounts and 12 Canon 85/f1.2 cameras.
Each mount is equipped with 2 cameras.
For each camera, the Apogee U9000X CCD was used, which gives
about 400 square degree of FOV. The total field of view of this system
is about 5000 sq.deg.

This message may be cited.


GRB_name: GRB160104A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18828
SUBJECT: GRB 160104A: Fermi GBM observation
DATE:    16/01/05 03:25:03 GMT
FROM:    Eric Burns at U of Alabama  <eb0016@uah.edu>

R. Hamburg (UAH) and Hoi-Fung Yu (MPE)
report on behalf of the Fermi GBM Team:

"At 11:24:13.22 UT on 04 January 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160104A (trigger 473599457 / 160104475), which
was also detected by the Swift/BAT (A. Melandri et al. 2016, GCN 18815).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 104
degrees.

The GBM light curve consists of one main peak
with a duration (T90) of about 10 s (50-300 keV).
The time-averaged spectrum from T0-3.200 s to T0+0.128 s is
adequately fit by a simple power law function with index -1.7 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(6.1 +/- 0.7)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.92 s in the 10-1000 keV band
is 1.7 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160104A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18829
SUBJECT: GRB 160104A: Swift-BAT refined analysis
DATE:    16/01/05 03:51:09 GMT
FROM:    Tilan Ukwatta at LANL  <tilan.ukwatta@gmail.com>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), A. Melandri (INAF-OAB),
T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent
telemetry downlink, we report further analysis of BAT
GRB 160104A (trigger #669319) (Melandri , et al., GCN
Circ. 18815).  The BAT ground-calculated position is
RA, Dec = 76.808, 11.334 deg which is
   RA(J2000)  =  05h 07m 13.9s
   Dec(J2000) = +11d 20' 01.2"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90%
containment). The partial coding was 100%.

The mask-weighted light curve shows a two-peak episode
with main peak starting ~T-3 sec, peaking at ~T+1 sec,
and ending around T+10 sec, where second weak
peak starts. The second pulse ends around ~T+20 sec.
T90 (15-350 keV) is 16.2 +- 2.5 sec (estimated
error including systematics).

The time-averaged spectrum from T-1.31 to T+17.65 sec is best
fit by a simple power-law model.  The power law index of the
time-averaged spectrum is 1.76 +- 0.19.  The fluence in the
15-150 keV band is 4.0 +- 0.5 x 10^-07 erg/cm2. The 1-sec peak
photon flux measured from T-0.16 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the
90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/669319/BA/


GRB_name: GRB160104A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18830
SUBJECT: GRB 160104A: Swift-XRT refined Analysis
DATE:    16/01/05 11:45:04 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

We have analysed 7.5 ks of XRT data for GRB 160104A (Melandri et al.
GCN Circ. 18815), from 63 s to 36.3 ks after the  BAT trigger. The data
comprise 914 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 18821).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.1 +/- 0.4, followed by a break at T+269 s to an alpha
of 0.53 (+0.14, -0.17). Flaring activity is observed between T0+200 s
and T0+2.0 ks.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.95 (+0.18, -0.08). The
best-fitting absorption column is  consistent with the Galactic value
of 2.7 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 3.7 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.7 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 2.7 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.95 (+0.18, -0.08)

If the light curve continues to decay with a power-law decay index of
0.53, the count rate at T+24 hours will be 0.01 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.7 x
10^-13 (5.2 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00669319.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160104A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18831
SUBJECT: GRB 160104A: Spectroscopic observations from 10.4m GTC
DATE:    16/01/05 12:09:05 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
J.P.U. Fynbo (DARK/NBI), N.R. Tanvir (U. Leicester), R. Sanchez-Ramirez
(IAA-CSIC) and S. Geier (GRANTECAN), report on behalf of a larger collaboration:

We observed the afterglow of GRB 160104A (Melandri et al. GCN18815,
Guidorzi et al. GCN18816) with OSIRIS on the 10.4 m GTC telescope, located
at the Roque de los Muchachos Observatory (La Palma, Spain). Observations 
started at 20:25 UT (9.0 hr after the GRB onset) and consisted of a 40 s 
acquisition image in i-band as well as 3x900s spectra using the R1000R grism which
covers the range between 5100 and 10000 AA with a resolution of R~800.

The acquisition image was obtained under good conditions with a seeing of 0.8".
The afterglow is clearly detected although it shows a strong decay in brightness
with respect to previous detections (Guidorzi et al. GCN18816, Saito et al. GCN 
18817, Yurkov et al. GCN 18820, Xin et al. 18823). As compared to USNO-B1.0
stars we measure a magnitude of i(Vega)=22.6, roughly equivalent to i(AB)=23.0.

The combined spectrum shows a clear continuum over the complete range 
with only one prominent absorption feature centred at 5889 AA, with an 
equivalent width of ~30 AA. There are also tentative absorptions features 
at ~5300 and ~5340 AA. There is no drop bluewards of the 5889 AA feature
which could otherwise be suggestive of a weak Ly-alpha at z=3.84. At a 
redshift of 2.80, the features could be consistent with CIV and the two SiIV, 
respectively. We are not able to establish a convincing solution for the redshift 
based on this evidence.


GRB_name: GRB160104A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18833
SUBJECT: GRB 160104A: Nishi-Harima MINT Observations
DATE:    16/01/06 04:49:49 GMT
FROM:    Tomohito Ohshima at Nishi-Harima Obs  <ohshima@nhao.jp>

GRB 160104A: Nishi-Harima MINT Observations

K. Morihana. J. Takahashi, Y. Takagi, S. Honda, T. Ohshima, and Y. Itoh
(Univ. of Hyogo), report on behalf of Nayuta team and OISTER collaboration:

We observed the field of GRB 160104A (Melandri et al. GCN 18815)
with Multiband Imager for Nayuta Telescope (MINT) attached to the Nayuta 2-m
telescope at the Nishi-Harima Astronomical Observatory.

The observations were started at 12:01 UT on 2016-01-4 (~35 minuets
after the burst).
We detected the optical afterglow in Rc band within the error circle of
Swift/XRT.

Photometric results of our observations are shown below.
We used nearby NOMAD catalogue stars for the photometric calibration.


# MID-UT Tmid-T0 T-EXP Rc_mag
----------------------------------------------------------------------
12:37:32 0.0509 4200s 21.6+/-0.5
----------------------------------------------------------------------
Tmid-T0: Elapsed time after the burst (day)
T-EXP: Total Exposure time (seconds)


GRB_name: GRB151225A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18836
SUBJECT: IPN Triangulation of GRB 151225A (short/hard)
DATE:    16/01/06 18:36:49 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The short-duration, hard-spectrum GRB 151225A (Kawakubo et al., GCN 
Circ. 18724) has been detected by CALET (CGBM), Konus-Wind, Swift (BAT), 
INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND), so far, at about 68950 s UT 
(19:09:10). The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   227.901 (15h 11m 36s) -18.302 (-18d 18' 07")
  Corners:
   228.654 (15h 14m 37s) -16.789 (-16d 47' 21")
   228.463 (15h 13m 51s) -16.574 (-16d 34' 25")
   227.176 (15h 08m 42s) -19.869 (-19d 52' 07")
   227.374 (15h 09m 30s) -20.101 (-20d 06' 03")
  ---------------------------------------------
The error box area is 3179 sq. arcmin, and its maximum
dimension is 3.7 deg (the minimum one is 15 arcmin).
The Sun distance was 43 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB151225_T68946/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming 
GCN Circular.


GRB_name: GRB151225A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18837
SUBJECT: Konus-Wind observation of GRB 151225A
DATE:    16/01/07 12:36:03 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration, intense GRB 151225A
(CALET detection: Kawakubo et al., GCN 18724;
IPN triangulation: Golenetskii et al., GCN 18836)
triggered Konus-Wind at T0=68946.508 s UT (19:09:06.508).

The burst light curve shows a  multipeaked structure
with a total duration of ~1.1 s.
The emission is seen up to ~2 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.17(-0.85,+1.79)x10^-6 erg/cm2,
and a 16-ms peak energy flux, measured from T0+0.416 s,
of 2.22(-0.79,+1.46)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.13(-0.48,+0.74),
and Ep = 360(-153,+741) keV (chi2 = 56/62 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.7 (chi2 = 56/61 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB151225_T68946/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160101A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18838
SUBJECT: Konus-Wind observation of GRB 160101A
DATE:    16/01/07 19:54:28 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, intense GRB 160101A
(MAXI detection: Itoh et al., GCN Circ. 18793;
Fermi GBM detection: Veres, GCN Circ. 18796)
triggered Konus-Wind at T0=2631.931 s UT (00:43:51.931).

The burst light curve shows a single pulse
with a total duration of ~4.6 s.
The emission is seen up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160101_T02631/

As observed by Konus-Wind, the burst
had a fluence of 1.47(-0.17,+0.21)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.214 s,
of 1.18(-0.30,+0.35)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.19(-0.19,+0.25),
the high energy photon index beta = -2.86(-7.14,+0.38),
the peak energy 143(-19,+20) keV
(chi2 = 103/83 dof).

The spectrum near the maximum count rate
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 5 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.06(-0.23,+0.27)
and Ep = 612(-175,+321) keV (chi2 = 26/41 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta <-2.0
(chi2 = 26/40 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160107A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18839
SUBJECT: GRB 160107A: MAXI/GSC detection
DATE:    16/01/08 02:25:37 GMT
FROM:    Yujin E. Nakagawa at JAXA  <nakagawa.yujin@jaxa.jp>

Y. E. Nakagawa (JAXA),  H. Negoro (Nihon U.), M. Serino (RIKEN), S. Ueno, H. Tomida,
S. Nakahira, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, M. Shidatsu, J. Sugimoto,
T. Takagi, M. Matsuoka (RIKEN), N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono,
T. Fujiwara (Tokyo Tech), Y. Kawakubo, A. Yoshida, T. Sakamoto, H. Ohtsuki (AGU),
H. Tsunemi, R. Imatani (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.),
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.),
Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.),
M. Yamauchi, D. Itoh, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at
22:19:56 UT on 2016 January 7. Assuming that the source flux was constant over the transit,
we obtain the source position at (R.A., Dec) = (299.670 deg, 6.413 deg) = (19 58 40, +06 24 46) (J2000)
with a statistical 90% C.L. elliptical error region with long and short radii of 0.20 deg and 0.15 deg,
respectively. The roll angle of long axis from the north direction is 151.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 366 +- 42 mCrab (4-10keV, 1 sigma error).
Without assumptions on the source constancy, we obtain a rectangular error box
for the transient source with the following corners:
(298.905 deg, 6.966 deg) = (19 55 37, +06 57 57) (J2000)
(299.190 deg, 7.260 deg) = (19 56 45, +07 15 36) (J2000)
(300.076 deg, 6.261 deg) = (20 00 18, +06 15 38) (J2000)
(299.789 deg, 5.968 deg) = (19 59 09, +05 58 03) (J2000)
There was no significant excess flux in the previous transit at 20:47 UT on 2016 January 7
and in the next transit at 23:52 UT on 2016 January 7 with an upper limit of 20 mCrab for each.

For more information: http://maxi.riken.jp/alert/novae/7394729601/7394729601.htm


GRB_name: GRB160104A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18841
SUBJECT: GRB 160104A: Continued MITSuME Akeno Optical Observation 
DATE:    16/01/08 06:41:52 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

T.Fujiwara, Y.Saito, T. Yoshii, Y. Yano, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160104A (A. Melandri et al., GCN
Circular #18815) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-01-04 11:24:56 UT (46 sec after the burst) and
we detected the optical counterpart in Rc and Ic band.
The measured magnitudes were listed as follows.

We obtained following results for the magnitudes.

T0+[sec]    MID-UT      T-EXP[sec]         g'              Rc                      Ic
-------------------------------------------------------------------------------------------------------
382            11:38:50        900                  > 20.6         18.9 +/- 0.1      18.3 +/- 0.2
13473         16:03:30        5880                 > 21.3         20.2 +/- 0.2      19.5 +/- 0.3
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB160107A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18844
SUBJECT: GRB 160107A: Fermi GBM observation
DATE:    16/01/08 14:23:48 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH) and C Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 2016-01-07 22:20:41.50 UT on 7 January 2016, the Fermi Gamma-Ray
Burst Monitor
triggered and located GRB 160107A (trigger 473898045 / 160107931), which
was also detected by the MAXI/GSC (Nakagawa et al., GCN 18839).
The GBM on-ground location is consistent with the MAXI position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 62 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 114 s (50-300 keV).
The time-averaged spectrum from T0-0.5 s to T0+110 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.79 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 54.5 +/- 2.6 keV.

The event fluence (10-1000 keV) in this time interval is
(3.63 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+27.7 s in the 10-1000 keV band
is 16.8 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak = 50.8 +/- 3.1 keV, alpha = -1.75 +/- 0.03 and beta = -2.47 +/- 0.14.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160107A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18845
SUBJECT: GRB 160107A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/01/09 00:48:30 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
K. Senuma, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), 
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 160107A (MAXI/GSC, Nakagawa et al. GCN Circ. 18839; 
Fermi-GBM, Veres et al. GCN Circ. 18844) triggered the CALET Gamma-Ray Burst Monitor 
(CGBM) at 22:20:43.20 UT on 7 January 2016.  The clear burst signal was detected 
by all instruments.  

The light curve of the HXM shows at least three peaks starting and ending at 
T0 and T0+25 sec, T0+25 sec and T0+50 sec, and T0+52 sec and T0+80 sec, 
respectively.  The T90 duration measured by the SGM data is 116.0 s +/- 12.5 sec (40-1000 keV).  

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.


GRB_name: GRB151229B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18852
SUBJECT: IPN Triangulation of GRB 151229B (extremely intense/long)
DATE:    16/01/11 19:48:08 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration, extremely intense GRB 151229B has been detected by 
Konus-Wind, Swift (BAT), and INTEGRAL (SPI-ACS), so far, at about 77063 
s UT (21:24:23). The burst was outside the coded field of view of the 
BAT. The burst was Mars-occulted to Odyssey.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
    RA(2000), deg                 Dec(2000), deg
   ---------------------------------------------
   Center:
     66.759 (04h 27m 02s)  -7.167 ( -7d 10' 00")
   Corners:
     71.595 (04h 46m 23s) -10.885 (-10d 53' 06")
     67.582 (04h 30m 20s)  -8.217 ( -8d 13' 00")
     62.910 (04h 11m 38s)  -3.557 ( -3d 33' 27")
     65.994 (04h 23m 59s)  -6.129 ( -6d 07' 46")
   ---------------------------------------------
The error box area is about 3 sq. deg,
and its maximum dimension is 11.3 deg
(the minimum one is 27 arcmin).
The Sun distance was 136 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB151229_T77056/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming 
GCN Circular.


GRB_name: GRB151229B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18854
SUBJECT: Konus-Wind observation of GRB 151229B
DATE:    16/01/12 16:33:23 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team, report:

The long-duration, extremely intense GRB 151229B
(IPN triangulation: Golenetskii et al., GCN Circ. 18852)
triggered Konus-Wind at T0=77056.981 s UT (21:24:16.981).

The burst light curve shows a bright multi-peaked pulse
with a duration of ~10 s (from ~T0+5 s to ~T0+15 s).
This extremely bright phase of the event passes into a weaker decaying
tail, which can be traced out to ~T0+100 s.
The emission in the main pulse is seen up to ~15 MeV.

As observed by Konus-Wind, the burst
had a fluence of 4.2(-0.1,+0.1)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+10.064 s,
of 7.1(-0.6,+0.6)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+28.672 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.65(-0.06,+0.06),
the high energy photon index beta = -2.12(-0.03,+0.03),
the peak energy 262(-13,+14) keV
(chi2 = 120/93 dof)

The spectrum near the maximum count rate
(measured from T0+9.984 to T0+10.240 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.33(-0.14,+0.16),
the high energy photon index beta = -2.51(-0.18,+0.14),
the peak energy 290(-30,+33) keV
(chi2 = 44/54 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB151229_T77056/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB151231A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18855
SUBJECT: IPN Triangulation of GRB 151231A
DATE:    16/01/12 20:45:20 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 151231A was detected by Fermi (GBM: Veres, et al., 
GCN Circ. 18787), Konus-Wind, Swift (BAT), and Mars-Odyssey (HEND), at 
about 38267 s UT (10:37:47). The burst was outside the coded field of 
view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    69.528 (04h 38m 07s) -61.010 (-61d 00' 36")
  Corners:
    70.843 (04h 43m 22s) -60.244 (-60d 14' 37")
    71.191 (04h 44m 46s) -60.345 (-60d 20' 41")
    68.143 (04h 32m 34s) -61.761 (-61d 45' 40")
    67.789 (04h 31m 09s) -61.652 (-61d 39' 07")
  ---------------------------------------------
The error box area is 1425 sq. arcmin, and its maximum
dimension is 2.1 deg (the minimum one is 11.6 arcmin).
The Sun distance was 91 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB151231_T38267/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming 
GCN Circular.


GRB_name: GRB160104A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18856
SUBJECT: GRB 160104A: Swift/UVOT Detection
DATE:    16/01/12 22:20:40 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F.E. Marshall (NASA/GSFC) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160104A
85 s after the BAT trigger (Melandri et al., GCN Circ. 18815).
A fading source consistent with the XRT position (Beardmore et al. GCN Circ. 18821)
and the optical afterglow position (Guidorzi et al. GCN Circ. 18816)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:07:11.05 =  76.79603 (deg.)
    Dec (J2000) =  11:19:25.5  =  11.32375 (deg.)
with an estimated uncertainty of 0.64 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               85          235          141         20.48 +/- 0.22
white             1180         1893           94        >20.5
v                  627         1252           78         18.92 +/- 0.32
b                  553         1869          136        >19.8
u                  297         1843          363        >20.5
w1                 677         1819          136        >20.1
m2                 825         5587          203        >20.1
w2                 602         5249          333        >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.26 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160107A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18857
SUBJECT: Konus-Wind observation of GRB 160107A
DATE:    16/01/13 13:36:22 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 160107A
(MAXI/GSC detection: Nakagawa et al., GCN 18839;
Fermi GBM observation: Veres & Meegan, GCN 18844;
CALET Gamma-Ray Burst Monitor detection: Nakahira et al., GCN 18845)
triggered Konus-Wind at T0=80440.646 s UT (22:20:40.646).

The burst light curve shows multiple, partly overlapped peaks
in the interval from ~T0-40 s to ~T0+110 s.
The emission is seen up to ~5 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.48(-0.28,+0.54)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+25.232 s,
of 5.86(-1.22,+1.39)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+106.752 s)
is best fit in the 20 keV - 5 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.75(-0.16,+0.18),
and Ep = 131(-36,+85) keV (chi2 = 83/77 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.0 (chi2 = 82/76 dof).

The spectrum near the peak count rate
(measured from T0+24.832 to T0+33.024 s)
is best fit in the 20 keV - 3 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.52(-0.16,+0.18),
and Ep = 198(-43,+86) keV (chi2 = 49/68 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.1 (chi2 = 49/67 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160107_T80440/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160113A
Detection_method: iPTF
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18859
SUBJECT: GRB 160113A: iPTF P48 Observations and Optical Transient Candidates 
DATE:    16/01/13 20:43:09 GMT
FROM:    Leo Singer at GSFC/iPTF  <leo.p.singer@nasa.gov>

L. P. Singer (NASA/GSFC), V. Bhalerao (IUCAA), S. B. Cenko (NASA/GSFC),
and M. M. Kasliwal (Carnegie) report on behalf of a larger collaboration:

Fermi GBM detected GRB 160113A (trigger 474370354 / bn160113398) at
2016-01-13 09:32:30.52. At 10:31:39, about 1 hour after the burst, we
began searching for optical counterparts using the Palomar 48-inch Oschin
telescope (P48).

We imaged 18 fields covering an area of 133 deg^2 in the 1-sigma
statistical+systematic region of the final Fermi GBM localization. We
estimate a 78% prior probability that these fields contain the true
location of the source. Sifting through candidate variable sources using
image subtraction and standard iPTF vetting procedures, we detected the
following optical transient candidates:

   name       RA        Dec      mag   t    Notes
----------------------------------------------------------------------------
                                Hostless
----------------------------------------------------------------------------
iPTF15flo 192.718034 +12.070614 20.29 1.99
iPTF15fls 187.113722  +7.078087 20.59 2.42 near elliptical galaxy at z=0.175
----------------------------------------------------------------------------
                   Hosts with spectroscopic redshifts
----------------------------------------------------------------------------
iPTF15flq 179.356225 +11.915619 20.02 2.10 z=0.165
iPTF15flm 191.925125 +13.140841 19.99 1.82 z=0.155
iPTF15fly 180.870452 +13.440016 19.41 2.10 z=0.090
iPTF15fln 192.218146 +15.660583 20.23 1.88 z=0.081, possibly fading
iPTF15flp 181.050555 +11.765386 19.28 1.52 z=0.296, BL Lac (Veron+ 2010)
----------------------------------------------------------------------------
                    Hosts with photometric redshifts
----------------------------------------------------------------------------
iPTF15flk 184.180492 +13.204215 20.66 1.58 z=0.382
iPTF15flr 181.775607  +9.400882 19.03 2.19 z=0.087
----------------------------------------------------------------------------
                           Possibly stellar
----------------------------------------------------------------------------
iPTF15flx 181.613083 +13.008351 20.33 1.52

Times are in hours since the GBM trigger. Magnitudes are in the Mould R
filter and in the AB system, calibrated with respect to point sources in
SDSS as described in Ofek et al. (2012, http://dx.doi.org/10.1086/664065).

We have scheduled all of the above sources for multi-band photometry on
the robotic Palomar 60" telescope (P60) tonight. We have requested Swift
target-of-opportunity observations of iPTF15flo.

Further observations of the above candidates, particularly iPTF15flo and
iPTF15fls, are encouraged to determine their nature and if one of them is
the optical afterglow of the GRB.

The diagram http://asd.gsfc.nasa.gov/Leo.Singer/Fermi474370354.pdf
shows the locations of our candidates and the P48 fields in relation to
the Fermi GBM 1- and 2-sigma statistical+systematic contours.


GRB_name: GRB160113A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18860
SUBJECT: GRB 160113A: Swift ToO observations
DATE:    16/01/13 22:31:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Fermi/GBM GRB 160113A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020594

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/GBM event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160113A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18861
SUBJECT: GRB 160113A: Fermi GBM detection
DATE:    16/01/14 00:57:55 GMT
FROM:    Eric Burns at U of Alabama  <eb0016@uah.edu>

O.J. Roberts (UCD) and E. Burns(UAH)
report on behalf of the Fermi GBM Team:

"At 09:32:30.52 UT on 13 January 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160113A (trigger 474370354 / 160113398).
The on-ground calculated location, using the GBM trigger
data, is RA = 187.3, DEC = 11.5, with an uncertainty
of 1.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

All of the optically variable sources detected by iPTF (Singer, GCN 18859)
are contained in the uncertainty region surrounding the final location.

The angle from the Fermi LAT boresight at the GBM trigger time is 98
degrees.

The GBM light curve consists of a smaller peak between
T-5 and T+10 followed by a bright peak from T+20 to about T+60
with a duration (T90) of about 25 s (50-300 keV).
The time-averaged spectrum from T0+25.60 s to T0+51.20 s is
best fit by a Band function with Epeak = 98 +/- 1 keV,
alpha = -0.40 +/- 0.03, and beta = -3.16 +/- 0.11

The event fluence (10-1000 keV) in this time interval is
(3.12 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+31.51 s in the 10-1000 keV band
is 27.7 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160113A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18862
SUBJECT: GRB 160113A: Swift-XRT observations
DATE:    16/01/14 10:15:05 GMT
FROM:    Sarah Gibson at U.of Leicester  <slg44@leicester.ac.uk>

A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA),
A. Maselli  (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester) and P.A. Evans
(U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/GBM-detected burst GRB 160113A (Roberts et al. GCN Circ. 18861),
collecting 2.7 ks of Photon Counting (PC) mode data between T0+46.7 ks
and T0+53.0 ks. The pointing was aimed at the optical transient
candidate iPTF15flo (Singer et al. GCN Circ. 18859).

No X-ray sources have been detected inside or close to the iPTF15flo
error region. The 3-sigma upper limit at the iPTF15flo position is
0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-13
erg cm^-2 s^-1 (assuming a typical GRB spectrum).

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020594.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB151225A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18863
SUBJECT: GRB 151225A: Correction to the trigger time of GCN 18724
DATE:    16/01/14 12:14:10 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

T. Sakamoto, Y. Kawakubo (AGU) and the CALET collaboration:

We would like to make the correction to the reported trigger 
time of the CALET Gamma-Ray Burst Monitor (CGBM) for GRB 151225A 
(Kawakubo et al., GCN Circ. 18724).  The correct trigger time is 
19:09:09.71 UT on 25 December 2015.  We apologize for any confusion.  

We would like to thank Dmitry Svinkin for pointing this out.


GRB_name: GRB160111A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18864
SUBJECT: IPN Triangulation of GRB 160111A (short/hard)
DATE:    16/01/14 13:12:50 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:

A short-duration GRB 160111A has been detected by Konus-Wind, Swift 
(BAT), and INTEGRAL (SPI-ACS), so far, at about 26526 s UT (07:22:06). 
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    43.835 (02h 55m 20s) +34.176 (+34d 10' 34")
  Corners:
    45.937 (03h 03m 45s) +28.261 (+28d 15' 40")
    40.903 (02h 43m 37s) +39.971 (+39d 58' 17")
    41.650 (02h 46m 36s) +40.070 (+40d 04' 11")
    46.604 (03h 06m 25s) +28.319 (+28d 19' 08")
  ---------------------------------------------
The error box area is 7.1 sq. deg, and its maximum
dimension is 12.6 deg (the minimum one is 34.3 arcmin).
The Sun distance was 118 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160111_T26526/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming 
GCN Circular.


GRB_name: GRB160111A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18865
SUBJECT: Konus-Wind observation of GRB 160111A
DATE:    16/01/14 14:05:13 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova and T. Cline,
on behalf of the Konus-Wind team, report:

The short-duration, hard-spectrum GRB 160111A
(IPN triangulation:  Golenetskii et al., GCN 18864)
triggered Konus-Wind at 26526.639 s UT (07:22:06.639).

The KW light curve shows a single pulse with a duration of ~0.3 s.
The emission is visible up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160111_T26526/

As observed by Konus-Wind, the burst had a fluence
of 2.4(-0.8,+1.0)x10^-6 erg/cm2, and a 16-ms peak flux,
measured from T0, of 9.7(-3.1,+4.1)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.128 s)
is best fit in the 20 keV - 10 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.06(-0.55,+0.84),
and the peak energy Ep = 682(-222,+367) keV,
chi2 = 15.6/19 dof.
Fitting this spectrum with the GRB (Band) function yields
the following model parameters:
the low-energy photon index alpha = -0.13 (-0.11,+0.08),
the high energy photon index beta < -2.35 (upper limit),
the peak energy Ep = 725 (-267, +321) keV,
chi2 = 15.7/18 dof.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB151231A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18866
SUBJECT: Konus-Wind observation of GRB 151231A
DATE:    16/01/14 14:07:57 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, intense GRB 151231A
(Fermi GBM observation: Veres, C Meegan & von Kienlin, GCN 18787;
CALET Gamma-Ray Burst Monitor detection: Moriyama et al., GCN18810;
IPN triangulation: Hurley et al., GCN 18855)
triggered Konus-Wind at T0=38267.351 s UT (10:37:47.351).

The burst light curve shows two emission episodes
with a total duration of ~91 s.
The emission is seen up to ~15 MeV.

As observed by Konus-Wind, the burst
had a fluence of 9.03(-0.64,+0.65)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+5.952 s,
of 1.27(-0.19,+0.19)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+77.056 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.81(-0.09,+0.10),
the high energy photon index beta = -2.57(-0.21,+0.14),
the peak energy Ep = 163(-10,+11) keV,
chi2 = 95/96 dof.

The spectrum near the peak count rate
(measured from T0 to T0+7.424 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.07(-0.07,+0.07),
the high energy photon index beta = -2.40(-0.19,+0.13),
the peak energy Ep = 216(-20,+22) keV,
chi2 = 61/63 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB151231_T38267/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160102A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18867
SUBJECT: Konus-Wind observation of GRB 160102A
DATE:    16/01/14 14:15:32 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team, report:

GRB 160102A, localized by MAXI/GSC (Itoh et al., GCN 18801),
was detected by Konus-Wind in the waiting mode.

The burst light curve shows a single pulse
started at ~T0(MAXI)-3.6 s with a total duration of ~6 s or less. Due to 
the coarse resolution of the waiting mode light curve we cannot 
unambiguously classify this GRB as a short.

As observed by Konus-Wind, the burst had a fluence of
8.66(-1.23,+3.01)x10^-7 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(MAXI)-0.668 s, of 1.49(-0.62,+0.78)x10^-7 erg/cm2/s
(both in the 20 - 1500 keV energy range).

Fitting the K-W 3-channel time-integrated spectrum (from ~T0(MAXI)-3.6 s 
to ~T0(MAXI)+2.28 s) by a simple power-law model yields a power law 
index of -2.05(-0.15,+0.23), chi2=0.5/1 dof.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB160102A/


GRB_name: GRB160104B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18869
SUBJECT: Konus-Wind observation of GRB 160104B
DATE:    16/01/15 09:48:49 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova,
and T. Cline, on behalf of the Konus-Wind team, report:

GRB 160104B, localized by MAXI/GSC (Kawakubo et al., GCN 18818)
was detected by Konus-Wind in the waiting mode.

The K-W light curve shows two distinct emission episodes.
The first one, from ~T0(MAXI)-25.9 s to ~T0(MAXI)+6.5 s,
corresponds to the MAXI trigger(T0(MAXI)=10:13:06.662 UT).
The second episode is separated from the first one by ~500 s
and lasts for ~165 s, from ~T0(MAXI)+515.8 s to ~T0(MAXI)+680.7 s.

The K-W ecliptic latitude response in both episodes is consistent
with the position of GRB 160104B. Taking this into account,
we suggest that both episodes observed by K-W belong to GRB 160104B
and the total duration of the burst is ~710 s.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB160104B/

As observed by Konus-Wind, the first episode had a fluence of
6.64(-0.81,+0.87)x10^-6 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(MAXI)-22.915 s, of 5.23(-0.88,+0.92)x10^-7 erg/cm2/s
(both in the 20 - 1200 keV energy range). The second episode had a
fluence of 1.36(-0.17,+0.17)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(MAXI)+615.933 s, of 3.59(-0.75,+0.75)x10^-7 erg/cm2/s
(both estimated in the same energy range).

Fitting the K-W 3-channel time-integrated spectrum of the first episode
(from ~T0(MAXI)-25.9 s to ~T0(MAXI)+6.5 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.8(-0.2,+0.3) and Ep = 489 (-114,+195) keV.

Fitting the K-W 3-channel time-integrated spectrum of the second episode
(from ~T0(MAXI)+515.8 s to ~T0(MAXI)+680.7 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.4(-0.2,+0.2) and Ep = 481 (-175,+580) keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB160113A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18871
SUBJECT: IPN Triangulation of GRB 160113A
DATE:    16/01/15 18:43:15 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 160113A has been detected by Fermi (GBM: Roberts 
and Burns, GCN Circ. 18861), Konus-Wind, INTEGRAL (SPI-ACS), Swift 
(BAT), and Mars-Odyssey (HEND), so far, at about 34350 s UT (09:32:30). 
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Corners:
    197.219 (13h 08m 52s) +18.468 (+18d 28' 03")
    197.479 (13h 09m 55s) +19.448 (+19d 26' 51")
    177.907 (11h 51m 38s) -19.867 (-19d 52' 02")
    178.597 (11h 54m 23s) -19.094 (-19d 05' 38")
  ---------------------------------------------
The error box area is 17.0 sq. deg, and its maximum
dimension is 42.8 deg (the minimum one is 45 arcmin).
The Sun distance was about 100 deg.

This box may be improved.

The intersection of the box with the 3 sigma contours of the GBM ground 
position was outside of the BAT coded FoV.

There is only one OT candidate, iPTF15fln (Singer et al., GCN Circ. 
18859), consistent with the box; the candidate was marked as possibly 
fading. The distance between the narrowest annulus (Konus-HEND annulus 
with 3 sigma half width of 0.375 deg) center line and the iPTF15fln is 
5.2 arcmin, supporting the association of the transient and the GRB.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB160106A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18872
SUBJECT: GRB 160106A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/01/16 04:52:16 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

K. Yamaoka (Nagoya U),  A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
K. Senuma, M. Moriyama, Y. Yamada (AGU), S. Nakahira (JAXA), Y. Asaoka, 
S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), 
S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) and the CALET collaboration:

The long-duration GRB 160106A (Fermi-GBM trigger #473813134; Konus-Wind 
triggered on 22:45:37.257 UT) triggered the CALET Gamma-Ray Burst Monitor 
(CGBM) at 22:45:34.70 UT on 6 January 2016.  The clear burst signal was detected 
by all instruments.  

The low energy light curve of the HXM shows two main episodes.  The first structure, 
which is composed of at least two spiky features, starts at T0, peaks at T0+2 sec (first spike) 
and at T0+8 sec (second spike) and apparently accompanied by an other hump, and 
then ends at T0+20 sec.  The second structure starts at T0+30 sec, peaks at T0+33 sec 
and ends at T0+45 sec.  The second structure looks invisible above 300 keV.  
The T90 duration measured by the SGM data is 39.3 s +/- 0.9 sec (40-1000 keV).  

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University. 


GRB_name: GRB160117A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18874
SUBJECT: GRB 160117A: Swift detection of a burst
DATE:    16/01/17 10:25:30 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 10:13:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160117A (trigger=670793).  Swift could not slew to the 
burst location due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 20.408, -0.627 which is 
   RA(J2000) = 01h 21m 38s
   Dec(J2000) = -00d 37' 37"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 30 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~6 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 00:56 UT on 2016 January 18. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160117B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18875
SUBJECT: GRB 160117B: Swift detection of a burst with optical counterpart
DATE:    16/01/17 14:14:09 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Sonbas (Adiyaman Univ.), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 13:59:27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160117B (trigger=670800).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 132.190, -16.340 which is 
  RA(J2000) = 08h 48m 46s
  Dec(J2000) = -16d 20' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 60 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 14:00:22.5 UT, 55.0 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 132.1953,
-16.3668 which is equivalent to:
   RA(J2000)  = 08h 48m 46.88s
   Dec(J2000) = -16d 22' 00.4"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 98 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.71
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 4.84e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 63 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 08:48:46.76 = 132.19484
  DEC(J2000) = -16:21:59.9  = -16.36664
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.32 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.07. 

Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

[GCN OPS NOTE(17jan16): Per N.Cucchiara's request, the Trigger number
in the first paragraph was changed from 670793 to 670800.]


GRB_name: GRB160113A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18876
SUBJECT: Konus-Wind observation of GRB 160113A
DATE:    16/01/17 14:23:27 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 160113A
(Fermi-GBM detection: Roberts & Burns, GCN 18861;
IPN triangulation: Hurley et al., GCN 18871)
triggered Konus-Wind at T0=34379.515 s UT (09:32:59.515).

The light curve shows a smooth pulse in the interval
from ~T0-5 s to ~T0+20 s, preceded by a much weaker pulse
around ~T0-28 s.
The emission is seen up to ~7 MeV.

As observed by Konus-Wind, the burst had a fluence
of 2.4(-0.1,+0.1)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+5.184 s, of 4.0(-0.3,+0.4)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+21.248 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.51 (-0.15,+0.17),
the high energy photon index beta = -3.55 (-0.83,+0.37),
the peak energy Ep = 97 (-4,+4) keV,
chi2 = 71.7/97 dof.

The spectrum near the peak count rate (measured from T0+0.256
to T0+8.192 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.24 (-0.19,+0.24),
the high energy photon index beta = -3.36 (-0.71,+0.39),
the peak energy Ep = 130 (-9,+8) keV,
chi2 = 71.5/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18877
SUBJECT: GRB 160117B: MASTER-Amur OT observations
DATE:    16/01/17 15:09:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, 
P.Balanutsa, A.Kuznetsov, V.V.Chazov,
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal University, Kourovka

A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik
Kislovodsk Solar Station of the Pulkovo Observatory

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160117B  (Sonbas et. al. 
GCN 18875) and made first exposition 19 sec after notice time and 35 sec 
after trigger time at 2016-01-17 14:04:35 UT.
But due to some problem with mount on strong frost  (-40 deg) we have a 
~4 deg. poining error and do not cover GRB160117B error box.
We correct this error and made first (60 sec exposure) image with 
GRB160117B error box at 2016-01-17 14:21:31 i.e. 1323 sec. after the 
trigger with upper limit 17.0.
On one of coadd image (with total exposure 180 sec, 1696 sec after the 
trigger)  we see   GRB160117B optical counterpart (Sonbas et. al. GCN 
18875) with 17.5 mag.
All magnitudes are unfiltered (0.2B+0.8R) with respect to number USNO B1.0 
stars.
The message may be cited.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18878
SUBJECT: GRB 160117B: LCOGT-SSO optical observations
DATE:    16/01/17 15:55:37 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE), D. Xu (NAOC/CAS), Y.-D. Hu (IAA-CSIC), Y. Qing 
(Geneva Observatory), Y.-H. Han (NAOC/CAS, HUST) report:

We observed the field of GRB 160117B (Swift trigger 670793, Sonbas et 
al., GCN 18875) using the LCOGT-1m located at the Siding Spring 
Observatory. Observations started at 14:20:45 UT on 2016-01-17 (i.e., 
1278 s after the burst), and a series of 180 s R-band images have been 
obtained. Further observations are ongoing.

The optical afterglow is detected at coordinates:

R.A. (J2000) = 08:48:46.74
Dec. (J2000) = -16:22:00.0

with an error radius of 0.2 arcsec, which is fully consistent with the 
UVOT position from GCN 18875. The afterglow has R = 18.3 +- 0.1 mag from 
the first 180 s exposure, calibrated with the nearby USNO B1 stars (R1 
magnitudes). The afterglow has been decaying rather slowly, with a decay 
slope of -0.5 +- 0.1 so far.


GRB_name: GRB160117B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18880
SUBJECT: GRB 160117B: Enhanced Swift-XRT position
DATE:    16/01/17 18:08:32 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.

Using 2434 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 160117B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 132.19454, -16.36675 which is equivalent
to:

RA (J2000): 08h 48m 46.69s
Dec (J2000): -16d 22' 00.3"

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160117B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18881
SUBJECT: GRB 160117B: Swift/UVOT Detection
DATE:    16/01/17 21:23:02 GMT
FROM:    Lea Hagen at PSU  <lea.zernow.hagen@gmail.com>

L. M. Z. Hagen (PSU) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160117B
64 s after the BAT trigger (Sonbas et al. GCN Circ. 18875). We detect
a fading source consistent with the XRT position  (Evans et al. GCN
Circ. 18880) and optical detections (Yurkov et al. GCN Circ. 18877,
Kruehler et al. GCN Circ. 18878).

The preliminary UVOT position is:
    RA  (J2000) =  08:48:46.76 = 132.19485 (deg.)
    Dec (J2000) = -16:22:00.1  = -16.36670 (deg.)
with an estimated uncertainty of 0.44 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system (Breeveld et al.
2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               63          213          147         18.24+-0.06
white              876         1025          147         18.26+-0.06
white             5700         5899          196         19.22+-0.09
white             7136         7335          196         19.48+-0.11
v                 6111         6311          196        >19.27
b                 5495         5695          196         19.84+-0.26
b                 6931         7131          196        >20.22
u                  275          525          245         17.84+-0.08
u                 5290         5489          196         19.13+-0.20
u                 6725         6925          196         19.14+-0.21
w1                5085         5285          196         18.75+-0.19
w1                6521         6721          196         18.90+-0.21
m2                6316         6515          196         19.22+-0.29
w2                5905         6105          196         19.18+-0.23
w2                7341         7533          188         19.50+-0.31

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160117A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18882
SUBJECT: GRB 160117A: Swift-BAT refined analysis
DATE:    16/01/17 23:00:29 GMT
FROM:    Craig Markwardt at NASA/GSFC  <craigm@milkyway.gsfc.nasa.gov>

D. M. Palmer, S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
  
Using the data set from T-173 to T+1029 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160117A (trigger #670793)
(Markwardt, et al., GCN Circ. 18874).  The BAT ground-calculated position is
RA, Dec = 20.367, -0.677 deg which is
    RA(J2000)  =  01h 21m 28.0s
    Dec(J2000) = -00d 40' 37.8"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve consists of a faint precursor from about
T-70 sec to T+30 sec, followed by brighter double-peaked structure from
about T+30 sec to T+115 sec. T90 (15-350 keV) is 118.58 +- 20.46 sec
(estimated error including systematics).

The time-averaged spectrum from T-46 to T+109 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.14 +- 0.11.  The fluence in the 15-150 keV band is 3.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+76 sec in the 15-150 keV band
is 1.4 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Please note that GRB 160117B was incorrectly marked with the same trigger
number as GRB 160117A in Sonbas et al. 2016 (GCN Circ. 18875).  The correct
trigger number for 160117A is above.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/670793/BA/


GRB_name: GRB160117B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18883
SUBJECT: GRB 160117B: Swift-XRT refined Analysis
DATE:    16/01/18 00:26:47 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), A. D'Ai (INAF-IASFPA), A. Maselli 
(INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P.
Osborne (U. Leicester) and E. Sonbas report on behalf of the Swift-XRT
team:

We have analysed 9.8 ks of XRT data for GRB 160117B (Sonbas et al. GCN
Circ. 18875), from 48 s to 24.8 ks after the  BAT trigger. The data
comprise 135 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 18880).

The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=0.77 (+0.25, -0.24).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.36 (+0.08, -0.07). The
best-fitting absorption column is  1.31 (+0.19, -0.18) x 10^21 cm^-2,
in excess of the Galactic value of 5.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.88 (+0.14, -0.13)
and a best-fitting absorption column of 8.8 (+3.7, -3.1) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.5 x 10^-11 (4.1 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.8 (+3.7, -3.1) x 10^20 cm^-2
Galactic foreground: 5.7 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.88 (+0.14, -0.13)

If the light curve continues to decay with a power-law decay index of
0.77, the count rate at T+24 hours will be 8.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.0 x
10^-13 (3.5 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00670800.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18884
SUBJECT: GRB 160117B: NOT optical afterglow observations
DATE:    16/01/18 01:27:54 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC and DARK/NBI),
R. Carrera (IAC-ULL), C.E. Martinez-Vazquez (IAC-ULL), P. Jakobsson (Univ. Iceland),
report on behalf of a larger collaboration:

We observed the optical counterpart of GRB 160117B (Sonbas et al., GCN 
18875; Yurkov et al., GCN 18877; Kruehler et al., GCN 18878) with the 
Nordic Optical Telescope (NOT) equipped with the ALFOSC camera.

In a 300-s exposure taken starting on Jan 18.028 UT (10.7 hr after the 
GRB), we measure for the afterglow a magnitude of R = 20.36 +- 0.11 
(Vega), calibrated against several nearby USNO-B1 stars (R1 magnitudes), 
with the uncertainty mostly due to the scatter in the USNO values.

[GCN OPS NOTE(18jan16): Per author's request, C.E.M-V was added, and the
affiliations were adjusted for  A.dU.P. and R.C..]


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18885
SUBJECT: GRB 160117B: iTelescope T17 optical observations
DATE:    16/01/18 04:04:33 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:

We have detected GRB 160117B optical afterglow at iTelescope observatory
T17 using 0.43-m f/6.8 astrograph and FLI ProLine E2V CCD. The observations
were started at 2016-01-17 14:34:35 (UT). Nine unfiltered images with 300 sec
exposure time were taken.

The afterglow was detected at the position RA 08:48:46.85 and DEC -16:22:00.0.

The following magnitude was obtained from the observations using USNO-B1.0
0736-0196371 (R1=16.52) as a comparison star:

Tmid(s)+T0     Filter          Exp. time          Mag               Mag. Err.
4367               Clear          9x300s             18.6CR          0.2

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GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18886
SUBJECT: GRB 160117B: VLT/X-shooter spectroscopy 
DATE:    16/01/18 05:35:54 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), G. Pugliese (API/UvA), 
D. Xu (NAOC/CAS), D. Malesani (DARK/NBI) report on behalf of a 
larger collaboration:

We observed the afterglow of GRB 160117B (Sonbas et al., GCN 18875; 
Yurkov et al., GCN 18877; Kruehler et al., GCN 18878, Malesani et al. 
GCN 18884, Hentunen et al. GCN 18885) with ESO's Very Large 
Telescope UT2 equipped with X-shooter. The spectra cover the range 
between 3000 and 18000 AA. Observations consisted of 4x1200s 
exposures, starting at 03:26 UT (13.45 hr after the GRB onset).

The optical counterpart is clearly detected in our grz acquisition images.

A preliminary analysis of the spectrum shows a clear continuum with 
absorption features due to FeII, MgII, as well as emission features of [OII], 
[OIII] and H-beta at a common redshift of 0.870, which we propose as 
redshift of the GRB.

We acknowledge the excellent support provided by the Paranal staff.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18887
SUBJECT: GRB 160117B: GROND optical/NIR afterglow observations
DATE:    16/01/18 10:54:19 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T.-W. Chen, T. Kruehler and J. Greiner (all MPE Garching) report on
behalf of the GROND team:

We observed the field of GRB 160117B (Sonbas et al., GCN 18875) 
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 
405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).

Observations started at 00:54 UT on 2016-01-18, about 11 hours after the 
GRB trigger. The optical afterglow (Sonbas et al., GCN 18875; Yurkov et 
al., GCN 18877; Kruehler et al., GCN 18878, Malesani et al.
GCN 18884, Hentunen et al. GCN 18885, de Ugarte Postigo et al. GCN 
18886) is clearly detected in our images.

Based on 29 min of total exposure in g'r'i'z' and 24 min in JHK at a 
midtime of 01:12 UT on 2016-01-18, we estimate the following preliminary 
magnitudes (all in the AB system):

  g' = 20.8 +- 0.1 mag
  r' = 20.7 +- 0.1 mag
  i' = 20.6 +- 0.1 mag
  z' = 20.4 +- 0.1 mag
  J  = 20.0 +- 0.2 mag
  H  = 19.8 +- 0.2 mag
  K  > 18.9 mag

Given magnitudes are calibrated against GROND zeropoints as well as 
2MASS field stars and are not corrected for the expected Galactic 
foreground extinction corresponding to a reddening of E_(B-V)=0.058 mag 
in the direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB160117A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18888
SUBJECT: GRB 160117A: Swift-XRT observations
DATE:    16/01/18 10:56:39 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Maselli  (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo
(INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R.
Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and D. M. Palmer report on behalf
of the Swift-XRT team:

We have analysed 4.6 ks of Photon Counting (PC) mode XRT data for the
Swift/BAT-detected burst GRB 160117A (Palmer et al. GCN Circ. 18882),
collected between T0+68.7 ks and T0+76.8 ks. 

One uncatalogued X-ray source has been detected inside or close to the
Swift/BAT error region, it is below the RASS limit and shows no
definitive signs of fading. Therefore, at the present time we cannot
confirm this as the afterglow. Details of this source are given below:

Source 1:
  RA (J2000):  20.3683  =  01:21:28.40
  Dec (J2000): -0.6542  =  -00:39:15.3
  Error: 3.9 arcsec (radius, 90% conf.)
  Count-rate: 0.0142 +/- 0.0020 ct s^-1
  Flux: (4.04 +/- 0.58)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00670793.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18890
SUBJECT: GRB 160104A: ISON-Ussuriysk optical observations
DATE:    16/01/18 21:20:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  E. Chornaya  (UAFO),  A. Matkin (UAFO, ISON), A. 
Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of 
larger GRB follow-up collaboration:

We observed the field of the GRB 160104A (Melandri  et al., GCN  18815) 
with SANTEL-650 (0.65m)  telescope of UAFO/ISON-Ussuriysk observatory 
starting on 2016-01-04 (UT) 12:21:43. We obtained 60 unfiltered images 
of 60 s exposure. We clearly detect optical afterglow (Guidorzi et al., 
GCN  18816) and preliminary photometry of a combined image is following

Date       UT start  t-T0  Filter  Exp.    OT   OT_err U_limit (3sigma)
                      (mid, days)   (s)

2016-01-04 12:21:43  0.0635 none    59*60  20.45 0.12  22.3


The photometry is based on nearby USNO-B1.0  stars:
USNO-B1.0_id R2
1013-0049708 15.14
1013-0049721 14.90
1013-0049703 16.30
1013-0049714 17.12

We also note the presence of a source  11" South-East of  m = 20.60 +/- 
0.15.


GRB_name: GRB151228B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18891
SUBJECT: GRB 151228B: AbAO optical upper limit
DATE:    16/01/18 21:23:00 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), R. Inasaridze (AbAO), V. Ayvazian (AbAO), A. Volnova 
(IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger 
GRB follow-up collaboration:

We observed the field of the Swift  GRB 151228B (Lien et  al., GCN 
18739) with AS-32 (0.7m) telescope of Abastumani Observatory starting on 
Dec. 29 (UT) 14:38:28.  We do not detect any source within
enhanced XRT error circle (Goad et al., GCN 18743):

Date       UT start     t-T0          Filter Exp.    UL(3 sigma)
            (mid, days)                       (s)

2015-12-29 14:38:28     0.69297       None  35*120   22.1

The photometry is based on nearby SDSS-DR9 stars:
SDSS-DR9_id             R_Lupton
J225738.02+080336.8 18.18
J225747.18+080340.7 16.86
J225736.71+080628.4 17.72
J225752.89+080438.1 17.46
J225726.79+080540.6 16.99


GRB_name: GRB160117A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18892
SUBJECT: GRB 160117A: Swift/UVOT Upper Limits
DATE:    16/01/19 02:00:12 GMT
FROM:    Lea Hagen at PSU  <lea.zernow.hagen@gmail.com>

L. M. Z. Hagen (PSU) and C. B. Markwardt (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160117A
68.7 ks after the BAT trigger (Markwardt et al. GCN Circ. 18874). No
optical afterglow consistent with the XRT position of Source 1 (Maselli
et al. GCN Circ. 18888) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first exposures
are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

v                75251        76158          885         >19.75
u                70499        70799          295         >19.80
w1               69593        80420         1226         >20.52
m2               68687        76854         1565         >20.90

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160119A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18893
SUBJECT: GRB 160119A: Swift detection of a burst
DATE:    16/01/19 03:18:51 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

F. E. Marshall (NASA/GSFC), D. N. Burrows (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 03:06:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160119A (trigger=671014).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 211.893, +20.474 which is 
   RA(J2000) = 14h 07m 34s
   Dec(J2000) = +20d 28' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows low level variability
followed by a peak from T+120 to T+180.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~142 sec after the trigger. 

The XRT began observing the field at 03:08:48.0 UT, 159.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 211.92111,
20.46161 which is equivalent to:
   RA(J2000)  = 14h 07m 41.07s
   Dec(J2000) = +20d 27' 41.8"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 104 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.08 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.4
(+2.60/-1.22) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 0.1 s image was 2.75e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 168 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03. 

Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18894
SUBJECT: GRB 160117B: Early iTelescope observation
DATE:    16/01/19 04:56:17 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

L. Izzo (URoma1/ICRA), T. Sakamot (AGU)

We observed the field of GRB 160117B (Sonbas et al., GCN 18875; Evans et al., GCN 18883; 
Yurkov et al., GCN 18877; Kruehler et al., GCN 18878; Malesani et al., GCN 18884; 
Hentunen et al., GCN 18885) with the iTelescope.Net (http://www.itelescope.net) 
T17 (Plane Wave CDK 0.43m) telescope located at the Siding Spring Observatory (Australia).  
A single image of 300 s was taken in the R filter, starting at 14:10:03 UT, 636 s 
after the GRB trigger. We detect the GRB optical afterglow candidate and obtain 
a photometry estimate of R = 17.523 +- 0.126 using the USNO-B1 catalog.  

An image of the field of view can be seen at http://goo.gl/aesww1


GRB_name: GRB160119A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18895
SUBJECT: GRB 160119A: NOT and GTC afterglow candidate
DATE:    16/01/19 05:06:13 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC and DARK/NBI), D. 
Xu (NAO/CAS), C.E. Martinez-Vazquez (IAC-ULL), A. Tejero (GTC), S. Geier 
(GTC), C.C. Thoene (IAA-CSIC), P. Jakobsson (Univ. Iceland) report on 
behalf of a larger collaboration.

We observed the field of GRB 160119A (Marshall et al., GCN 18893) with 
the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. 
Observations were carried out in the SDSS r and i bands, starting on 
2015 Jan 19.151 UT (31 min after the GRB trigger).

We also observed the same field using the Gran Telescopio Canarias 
(GTC), equipped with OSIRIS, starting on Jan 19.164 UT (50 min after the 
GRB trigger), also in the r and i bands.

Compatible with the current XRT localization (3.6" radius, SPER-based; 
http://www.swift.ac.uk/xrt_positions/), we detect a single, faint 
optical source, at coordinates (J2000):

RA = 14:07:41.35
Dec = +20:27:40.1

with an uncertainty of <0.5".

Using nearby stars from the SDSS catalog, we measure from the NOT image 
a magnitude r = 22.75 +- 0.15 (AB). This magnitude measurement is 
affected by the extended glare of a nearby bright star, making 
background subtraction less accurate than normal. This object is also 
seen, faintly, in the short GTC images (30-60 s exposure).

The object seems marginally brighter than the SDSS detection limit. 
However, despite ~20 min time difference between the NOT and GTC data, 
we do not measure obvious variability between the two epochs, as it is 
common among GRB afterglows close to the trigger. Further observations 
will be necessary to ascertain the relation of this object with the GRB.


GRB_name: GRB160119A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18896
SUBJECT: GRB 160119A: Enhanced Swift-XRT position
DATE:    16/01/19 08:13:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1310 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160119A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 211.92183, +20.46094 which is equivalent
to:

RA (J2000): 14h 07m 41.24s
Dec (J2000): +20d 27' 39.4"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160119A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18897
SUBJECT: GRB 160119A: Swift-XRT refined Analysis
DATE:    16/01/19 11:13:02 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU),
T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), V.
D'Elia (ASDC) and F.E. Marshall report on behalf of the Swift-XRT team:

We have analysed 8.4 ks of XRT data for GRB 160119A (Marshall et al.
GCN Circ. 18893), from 149 s to 18.2 ks after the  BAT trigger. The
data comprise 456 s in Windowed Timing (WT) mode (the first 9 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by Goad
et al. (GCN Circ. 18896).

The late-time light curve (from T0+4.9 ks) can be modelled with a
power-law decay with a decay index of alpha=0.59 (+/-0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.86 (+/-0.05). The
best-fitting absorption column is  2.57 (+0.23, -0.22) x 10^21 cm^-2,
in excess of the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.11 (+/-0.11) and a
best-fitting absorption column of 1.9 (+/-0.3) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.3 x 10^-11 (4.7 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.9 (+/-0.3) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: 8.0 sigma
Photon index:      2.11 (+/-0.11)

If the light curve continues to decay with a power-law decay index of
0.59, the count rate at T+24 hours will be 0.056 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x
10^-12 (2.6 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00671014.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18898
SUBJECT: GRB 160117B: further NOT optical observations of the afterglow
DATE:    16/01/19 15:16:17 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), D. Xu (NAOC/CAS), C.E. Martinez-Vazquez 
(IAC-ULL), and P. Jakobsson (Univ. Iceland) report on behalf of a larger 
collaboration.

We observed again the optical counterpart of GRB 160117B (Sonbas et al., 
GCN 18875), using the NOT equipped with the AlFOSC camera. Our 
observation was carried out in the R band and was composed of 4x300 s 
exposures, with mean time January 19.10 UT (1.52 days after the GRB).

Compared to our previous observation (Malesani et al., GCN 18884), we 
find a decay slope alpha = 1.10 +- 0.05 (assuming a single power-law 
decay F propto t^-alpha). This decay is steeper than what reported at 
early time by Kruehler et al. (GCN 18878).


GRB_name: GRB160119A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18899
SUBJECT: GRB 160119A: Swift-BAT refined analysis
DATE:    16/01/19 15:29:16 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160119A (trigger #671014)
(Marshall, et al., GCN Circ. 18893).  The BAT ground-calculated position is
RA, Dec = 211.916, 20.453 deg which is
    RA(J2000)  =  14h 07m 39.8s
    Dec(J2000) = +20d 27' 09.1"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.

The mask-weighted light curve shows some low-level activity from about T+20 sec
to T+100 sec.  This is followed by a single main peak starting at T+110 sec,
with a broad peak from T+140 to T+155 sec, and a slow decay out to T+200 sec.
T90 (15-350 keV) is 116 +- 14 sec (estimated error including systematics).

The time-averaged spectrum from T+32.62 to T+190.39 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.68 +- 0.05.  The fluence in the 15-150 keV band is 7.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+146.06 sec in the 15-150 keV band
is 2.9 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/671014/BA/


GRB_name: GRB160117B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18900
SUBJECT: GRB 160117B: RATIR Optical and NIR Observations
DATE:    16/01/19 16:12:22 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara@nasa.gov>

Antonino Cucchiara(GSFC/STScI),Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC),William H. Lee (UNAM), Michael G. Richer (UNAM), 
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),  Eleonora 
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JosÃ© A. 
de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM), Carlos 
RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), 
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160117B (Sonbas et al., GCN 18875) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/01 19.19 to 2016/01 19.36 UTC (38.57
to 42.63 hours after the BAT trigger), obtaining a total of 2.76 hours
exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle, in comparison with the USNO-B1 
and 2MASS catalogs, we obtain the following upper limits (3-sigma):


  r > 23.57
  i > 23.55
  z > 19.97

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro 
MÃ¡rtir.


GRB_name: GRB160119A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18901
SUBJECT: GRB 160119A: RATIR Optical and NIR Observations
DATE:    16/01/19 16:20:11 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara@nasa.gov>

Antonino Cucchiara (GSFC/STScI),Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC),William H. Lee (UNAM), Michael G. Richer (UNAM), 
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Eleonora 
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JosÃ© 
A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM), 
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), 
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160119A (Marshall, et al., GCN 18893) with the 
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m 
Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on Sierra San 
Pedro MÃ¡rtir from 2016/01 19.36 to 2016/01 19.54 UTC (5.61 to 9.76 hours after 
the BAT trigger), obtaining a total of 3.20 hours exposure in the r, i, and z bands. 

We identified the source reported by Malesani et al., GCN 18895. 
In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the 
following detections and upper limits (3-sigma): 

 r   23.78 +/- 0.28 
 i   23.26 +/- 0.17 
 z   > 20.78 

These magnitudes are in the AB system and are not corrected for Galactic 
extinction in the direction of the GRB. We thank the staff of the Observatorio 
AstronÃ³mico Nacional in San Pedro MÃ¡rtir.


GRB_name: GRB160119A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18902
SUBJECT: GRB 160119A: GROND optical/NIR afterglow observations
DATE:    16/01/19 18:52:32 GMT
FROM:    Ting-Wan Chen at MPE  <jchen@mpe.mpg.de>

T.-W. Chen, T. Kruehler, F. Knust, J. Greiner (all MPE Garching), and D. A. Kann (TLS Tautenburg) report on behalf of the GROND team:

We observed the field of GRB 160119A (Swift trigger 671014; Marshall et al., GCN #18893) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).

Observations started at 07:53 UT on 2016-01-19, about 4.8 hours after the GRB trigger. 

Our images were performed at an average seeing of 1.8" and at an average airmass of 2.0. Based on 19 min of total exposure in g'r'i'z' and 16 min in JHK at a midtime of 08:38 UT on 2016-01-19, we estimate the detection and upper-limit magnitudes (all in the AB system):

g' > 23.9 mag,
r' = 23.6 +- 0.2 mag,
i' = 22.9 +- 0.2 mag,
z' = 22.5 +- 0.2 mag,
J > 20.5 mag,
H > 20.2 mag, and
K > 19.1 mag.

Our observation was about 4.8 hours later than the NOT followup observed by Malesani et al. (GCN #18895), and about 0.2 hours earlier than the RATIR observation by Cucchiara et al. (GCN #18901).
The fading of r'-band magnitudes between NOT and GROND is about 0.85 mag, and within the uncertainties between GROND and RATIR. The decline rate is about 0.18 mag/hr, which confirms the afterglow nature.

The given magnitudes are derived based on calibrating the images against SDSS and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E(B-V)= 0.03 mag in the direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB160119A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18904
SUBJECT: GRB 160119A: Swift/UVOT Upper Limits
DATE:    16/01/20 13:46:13 GMT
FROM:    Marissa McCaule at PSU  <marissamc@swift.psu.edu>

L. M. McCauley (PSU) and F. E. Marshall (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160119A
169 s after the BAT trigger (Marshall et al., GCN Circ. 18893).
No optical afterglow consistent with the optical position
(Malesani et al. GCN Circ. 18895)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC              169        319          147      >21.04
white                 607       7398          478      >21.06
v                     657      34548         4935      >20.99
b                     755       7355          471      >20.19
u                     327       7150          716      >20.26
uvw1                 1460      30371         3157      >21.07
uvm2                 6540      29669         3739      >21.45
uvw2                 6130       6330          196      >19.89

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160119A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18905
SUBJECT: GRB160119A: BOOTES-2/TELMA Early Upper Limits
DATE:    16/01/20 14:59:20 GMT
FROM:    Juan Carlos Tello at IAA-CSIC  <jtello@iaa.es>

J. C. Tello, S. R. Oates (IAA-CSIC), Martin Jelinek (Astronomical Institute
ASU-AVCR Ondrejov) and A. J.Castro-Tirado (IAA-CSIC & ISA-UMA), on behalf
of a larger collaboration, report:

"The 60 cm BOOTES-2/TELMA robotic telescope (Malaga, Spain) automatically
responded to the Swift trigger of GRB 160119A (Marshall et al., GCN 18893).
The first unfiltered images where obtained at 03:07:59 (111 seconds after
the burst, 9.44 seconds after receiving the GCN alert).

No credible source is found when combining the first 40 unfiltered images
of 3 seconds exposure. The combined image ranges from 03:07:59 UT -
03:10:28 UT (1.85-4.33 minutes after the burst) and results in a limiting
magnitude of 19.5 when compared to SDSS-R6 r filter catalog.

We also observed the field using the i filter, no credible source is found
either when combining 6x60s exposures. The combined image ranges from
03:16:54 UT - 03:40:01 UT (10.7-33.9 minutes after the burst) and results
in a limiting magnitude of 18.5 when compared to SDDS-R6 catalog."


GRB_name: GRB160119A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18906
SUBJECT: GRB 160119A: afterglow confirmation from the NOT
DATE:    16/01/20 16:36:39 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), D. Xu (NAOC/CAS), P. Jakobsson (Univ. Iceland), 
C.E. Martinez-Vazquez (IAC-ULL), S. Murabito (IAC-ULL) report on behalf 
of a larger collaboration:

We observed again the field of GRB 160119A (Marshall et al., GCN 18893) 
with the Nordic Optical Telescope (NOT) equipped with the AlFOSC camera. 
Observations start on January 20.14 UT (1.01 days after the GRB) and 
consisted of 3x600 s in the SDSS r band.

No object is detected at the position of the candidate afterglow 
(Malesani et al., GCN 18895; Cucchiara et al., GCN 18901; Chen et al., 
GCN 18902), down to a limiting magnitude r > 23.8 AB (3 sigma), 
calibrated against nearby SDSS stars.

Compared to our previous observation (Malesani et al., GCN 18895), the 
new measurement conclusively establishes fading, thus confirming that 
this source is the afterglow of GRB 160119A, as already suggested by 
Chen et al. (GCN 18902).


GRB_name: GRB160117B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18907
SUBJECT: GRB 160117B: further RATIR observations 
DATE:    16/01/20 19:15:17 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara@nasa.gov>

Antonino Cucchiara(GSFC/STScI),Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC),William H. Lee (UNAM), Michael G. Richer (UNAM), 
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),  Eleonora 
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JosÃ© A. 
de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM), Carlos 
RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), 
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed again the field of GRB 160117B (Sonbas et al., GCN 18875)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org <http://www.ratir.org/>) 
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional 
on Sierra San Pedro MÃ¡rtir from 2016/01 20.21 to 2016/01 20.36 UTC (63.10
to 66.61 hours after the BAT trigger), obtaining a total of 2.51 hours
exposure in the r and i bands.

In comparison with the USNO-B1 and 2MASS catalogs, we
obtain the following detections:

  r 23.04 +/- 0.27
  i 22.20 +/- 0.12 

Also, after further analysis of the RATIR full dataset on GRB 160117B 
from 2016/01 19.19 to 2016/01 19.36 UTC (38.57 to 42.63 hours after the BAT trigger)
we report the following detections in r and i bands: 

  r  22.30 +/- 0.11
  i  21.96 +/- 0.08

The previously reported, incorrect, limits should not to be considered (GCN 18900).

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro 
MÃ¡rtir. We thank D. Malesani, the NOT, and GROND teams for encouraging 
us to reconsider our earlier observations.


GRB_name: GRB160117B
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18908
SUBJECT: GRB 160117B: VLA Detection
DATE:    16/01/21 01:51:32 GMT
FROM:    Kate Alexander at Harvard  <kalexander@cfa.harvard.edu>

K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), E. Berger
(Harvard), and W. Fong (U. Arizona) report on behalf of a larger
collaboration:

We observed GRB 160117B (Sonbas et al, GCN 18875) at multiple frequencies
with the Karl G. Jansky Very Large Array (VLA) beginning 2016 January 20.28
UT (2.70 days after the burst). At a mean frequency of 21.8 GHz, we detect
a radio source with a preliminary flux density of ~ 0.1 mJy at

RA = 08:48:46.737 +/- 0.5â€
Dec = -16:22:00.09 +/- 0.2â€

consistent with the enhanced Swift/XRT position (Evans et al., GCN 18880)
and the optical position (Crueler et al,. GCN 18878; Hagen and Sonbas, GCN
18881). Follow-up observations are planned.

We thank the VLA staff for rapidly executing these observations.


GRB_name: GRB160119A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18909
SUBJECT: GRB 160119A: VLA Detection
DATE:    16/01/21 01:55:34 GMT
FROM:    Kate Alexander at Harvard  <kalexander@cfa.harvard.edu>

K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger
(Harvard) report on behalf of a larger collaboration:

We observed GRB 160119A (Marshall et al, GCN 18893) at multiple frequencies
with the Karl G. Jansky Very Large Array (VLA) beginning 2016 January 20.44
UT (1.31 days after the burst). At a mean frequency of 21.8 GHz, we detect
a radio source with a preliminary flux density of ~ 0.13 mJy at

RA = 14:07:41.295 +/- 0.36â€
Dec = +20:27:40.04 +/- 0.11â€

consistent with the enhanced Swift/XRT position (Goad et al., GCN 18896)
and the optical position (Malesani et al,. GCN 18895). Follow-up
observations are planned.

We thank the VLA staff for rapidly executing these observations.


GRB_name: GRB160117A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18910
SUBJECT: GRB 160117A: Swift-XRT afterglow detection
DATE:    16/01/21 07:19:22 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Maselli  (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo
(INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R.
Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and D. M. Palmer report on behalf
of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Swift/BAT-detected burst GRB 160117A (Palmer et al. GCN Circ. 18882).
The observations now extend from T0+68.7 ks to T0+304.5 ks. The source
previously reported by Maselli et al. (GCN Circ. 18888), "Source 1", is
fading with 3-sigma significance, and is therefore likely the GRB
afterglow.  The position of this source is RA, Dec=20.3683, -0.6541
which is equivalent to:

RA (J2000): 01:21:28.39
Dec(J2000): -00:39:14.7

with an uncertainty of 3.8 arcsec (radius, 90% confidence).  This
position is 65 arcsec from the Swift/BAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.1 (+0.5, -0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.7 (+0.9, -0.6). The
best-fitting absorption column is  1.2 (+0.6, -0.4) x 10^22 cm^-2, in
excess of the Galactic value of 4.4 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 2.6 x 10^-11 (3.7 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.2 (+0.6, -0.4) x 10^22 cm^-2
Galactic foreground: 4.4 x 10^20 cm^-2
Excess significance: 5.2 sigma
Photon index:      3.7 (+0.9, -0.6)

The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00670793/index_1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00670793.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160119A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18911
SUBJECT: Konus-Wind observation of GRB 160119A
DATE:    16/01/21 12:57:45 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 160119A (Swift-BAT trigger #671014:
Marshall, et al., GCN Circ. 18893, Stamatikos, et al.,
GCN Circ. 18899) was detected by Konus-Wind in the waiting mode.

The burst light curve shows a weak count rate increase
starting from ~T0(BAT)+9 s. The main phase of the event
consists of a single peak from ~T0(BAT)+120 s to ~T0(BAT)+175 s.
As calculated from the Bayesian block division,
the total duration of the burst is ~215 s.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB160119A/

As observed by Konus-Wind, the burst had a fluence of
1.68(-0.18,+0.19)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+144.3 s, of 6.39(-0.85,+0.89)x10^-7 erg/cm2/s
(both in the 20 - 1200 keV energy range).

Modelling the K-W 3-channel time-integrated spectrum
(measured from ~T0(BAT)+8.9 s to ~T0(BAT)+223.8 s)
by the cutoff power law yields the following model parameters:
the photon index alpha = -1.73(-0.12,+0.15),
and the peak energy Ep = 189(-53,+231) keV.

Modelling the 3-channel spectrum near the peak count rate
(from ~T0(BAT)+138.4 s to ~T0(BAT)+150.2 s)
by the cutoff power law yields the following model parameters:
the photon index alpha = -1.16(-0.13,+0.15),
and the peak energy Ep = 187(-25,+34) keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB160121A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18912
SUBJECT: GRB 160121A: Swift detection of a burst
DATE:    16/01/21 14:02:13 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

L. M. Z. Hagen (PSU), D. N. Burrows (PSU), P.A. Evans (U Leicester),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
F. E. Marshall (NASA/GSFC), L. M. McCauley (PSU),
K. L. Page (U Leicester) and B. Sbarufatti (INAF-OAB/PSU) report on
behalf of the Swift Team:

At 13:50:37 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160121A (trigger=671231).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 109.079, -23.578 which is 
   RA(J2000) = 07h 16m 19s
   Dec(J2000) = -23d 34' 40"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single FRED-
shaped peak with a duration of about 15 sec.  The peak count rate
was ~1700 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 13:52:08.7 UT, 91.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 109.0890, -23.5920
which is equivalent to:
   RA(J2000)  = 07h 16m 21.35s
   Dec(J2000) = -23d 35' 31.3"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 60 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.26
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of nominal 250.000 seconds with the U filter
starting 151 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. Data from the 2.7'x2.7' sub-image are
not available at this time. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18.0 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.66. 

Burst Advocate for this burst is L. M. Z. Hagen (lea.zernow.hagen AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18913
SUBJECT: GRB 160121A: MASTER-Amur observations 
DATE:    16/01/21 14:21:03 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, 
P.Balanutsa, A.Kuznetsov, V.V.Chazov,
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal University, Kourovka

A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik
Kislovodsk Solar Station of the Pulkovo Observatory

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160121A (Hagen et al GCN 
18912) 22 sec after notice time and 34 sec after trigger time at 2016-01-21 13:51:15 UT.
On our first (10s exposure)  set we haven't found optical transient  within 
SWIFT.
The 5-sigma upper limit has been about 15.3 mag
The message may be cited.


GRB_name: GRB160117B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18915
SUBJECT: GRB 160117B: TNG spectroscopy and redshift confirmation
DATE:    16/01/21 15:31:14 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. DElia (INAF-OAR/ASI-ASDC), A. Melandri (INAF-OAB), L. A. Antonelli (INAF-OAR/ASI-ASDC), D. Malesani (DARK/NBI) report on behalf of the CIBO collaboration:

We observed the afterglow of GRB 160117B (Sonbas et al., GCN 18875) with the TNG equipped with DOLORES and the LR-B grism. The spectrum was acquired on 2016-01-18 and covers the range between 3000 and 7800 AA. The observation consisted of 2x1800 s exposures, starting at 01:31 UT (11.50 hr after the trigger).

The optical counterpart is detected in the acquisition images with a magnitude of R = 20.3 +/- 0.2 at 11.5 hr after the GRB trigger, calibrated against USNO-B1 stars.

The spectrum has a low S/N ratio but shows a clear continuum. Two absorption and an emission features are consistent with the Mg II doublet and the [O II] line at a redshift of z = 0.86 +/- 0.01, thus confirming what reported by de Ugarte Postigo et al. (GCN 18886).

We thanks the TNG staff for excellent support, in particular Hristo Stoev and Luca Di Fabrizio.


GRB_name: GRB160117B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18916
SUBJECT: GRB 160117B: RATIR continued observations
DATE:    16/01/21 17:11:22 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara@nasa.gov>

Antonino Cucchiara(GSFC/STScI),Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC),William H. Lee (UNAM), Michael G. Richer (UNAM), 
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),  Eleonora 
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JosÃ© A. 
de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM), Carlos 
RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), 
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We continued observing the field of GRB 160117B with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org <http://www.ratir.org/>) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/01 21.17 to 2016/01 21.51 UTC (86.20
to 94.28 hours after the BAT trigger), obtaining a total of 6.26 hours
exposure in the r and i bands.


The optical afterglow is still detected and in comparison with the USNO-B1 
catalog, we obtain the following detections:


  r 22.91 +/- 0.17
  i 22.39 +/- 0.10
  

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro 
MÃ¡rtir.

[GCN OPS NOTE(21jan16): The GRB name in the Subject-line was corrected
"16017" --> "160117".]


GRB_name: GRB160121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18917
SUBJECT: GRB 160121A: 1.8m MOA optical afterglow detection
DATE:    16/01/21 22:19:41 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>

S. R. Oates, J. C. Tello (IAA-CSIC Granada), P. Tristram (Mt. John Univ. Observatory),
I. Bond (Massey Univ.),  S. Takahiro (Osaka Univ.), P. Yock (Univ. of Auckland) and
A. J. Castro-Tirado (IAA-CSIC & ISA-UMA) report on behalf of a larger collaboration:

We observed the field of GRB 160121A (Hagen  et al., GCN 18912) with the 1.8m MOA-II
telescope at Mt John University Observatory in New Zealand. A series of 60s exposures
were taken with the R-band filter beginning 4.38 min (13:55:0 UT on 21-01-2016) after
the Swift trigger 671231.

We detect a single source at the edge of the Swift-XRT error circle (Hagen  et al., GCN 18912),
which we propose is the afterglow, at coordinates:

RA (J2000) = 07:16:21.16
Dec (J2000) = -23:35:31.6

with an error of around 0.5".

In the first exposure, ~292s after the trigger, we measure R ~19.7+\-0.2.
The light curve appears to increase slightly in brightness, plateauing
around 500s with a magnitude ~19. The light curve begins to decay around
1200s after the trigger.

Magnitudes and upper limits are calibrated against USNO-B1 catalogue and
are not corrected for the significant Galactic extinction corresponding to a
reddening of E_B-V = 0.53 mag (Schlafly & Finkbeiner 2011).


GRB_name: GRB160121A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18918
SUBJECT: GRB 160121A: Enhanced Swift-XRT position
DATE:    16/01/21 22:44:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2518 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 160121A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 109.08819, -23.59221 which is equivalent
to:

RA (J2000): 07h 16m 21.17s
Dec (J2000): -23d 35' 32.0"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160121A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18919
SUBJECT: GRB 160121A: Swift-BAT refined analysis
DATE:    16/01/21 22:47:14 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), L. M. Z. Hagen (PSU), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), (i.e. the Swift-BAT team):

Using the data set from T-239 to T+340 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160121A (trigger #671231)
(Hagen, et al., GCN Circ. 18912).  The BAT ground-calculated position is
RA, Dec = 109.080, -23.590 deg which is
    RA(J2000)  =  07h 16m 19.1s
    Dec(J2000) = -23d 35' 25.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.

The mask-weighted light curve shows a single peak starting at T-4 sec,
peaking at T+3 sec and returning to baseline by T+14 sec. T90 (15-350 keV)
is 12.0 +- 2.4 sec (estimated error including systematics).

The time-averaged spectrum from T-0.03 to T+14.97 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.77 +- 0.13.  The fluence in the 15-150 keV band is 6.1 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.76 sec in the 15-150 keV band
is 1.2 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/671231/BA/


GRB_name: GRB160121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18920
SUBJECT: GRB 160121A: TSHAO optical afterglow confirmation
DATE:    16/01/22 00:36:48 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Kusakin 
(Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) 
report on behalf of a larger GRB follow-up collaboration:

We observed the field of the Swift GRB 160121A (Hagen  et al., GCN 18912) 
with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory 
starting on Jan. 21 (UT) 16:04:44.  We obtained several images in R filter. 
We detect afterglow  (Oates et al., GCN 18917) in a combined image within 
center of the enhanced Swift-XRT position (Osborne et al., GCN 18918). 
Preliminary photometry of the afterglow is following

Date       UT start    t-T0     Filter  Exp.    OT     Err
                        (mid, days)      (s)

2016-01-21 16:04:44    0.12598  R       29*180  20.26  0.22


The photometry is based on nearby USNO-B1.0 stars.

USNO-B1.0_id    R2
0664-0122909    16.87
0664-0122918    16.73
0664-0122943    17.72
0664-0123015    18.03
0663-0123485    16.91


GRB_name: GRB160121A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18921
SUBJECT: GRB 160121A: GROND Afterglow observations
DATE:    16/01/22 08:36:42 GMT
FROM:    Corentin Delvaux at MPE  <delvaux@mpe.mpg.de>

C. Delvaux (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner
(MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 160121A (Swift trigger 671231; Hagen et al.,
GCN #18912) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 04:09 UT on 22-01-2016, 14.3hrs after the GRB
trigger. They were performed at an average seeing of 0.9" and at an
average airmass of 1.0.

We clearly detect the afterglow at the position reported by Oates et al.
(GCN#18917) and Mazaeva et al. (GCN#18920).

Based on the first 72 min of total exposures in g'r'i'z' and 60 min in
JHK, at a midtime of 04:49 UT, we estimate preliminary magnitudes and
upper limits (all in AB system) of

g' = 22.6 +/- 0.1 mag
r' = 21.2 +/- 0.1 mag,
i' = 21.1 +/- 0.1 mag,
z' = 21.0 +/- 0.1 mag,
J =  19.6 +/- 0.1 mag,
H =  19.3 +/- 0.1 mag,
K > 19.1 mag.

The given magnitudes and limits are derived based on calibrating the
images against GROND zeropoints and 2MASS field stars and are not
corrected for the Galactic foreground extinction corresponding to a
reddening of E_(B-V)= 0.53 in the direction of the burst (Schlafly and
Finkbeiner 2011).


GRB_name: GRB160121A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18922
SUBJECT: GRB 160121A: Swift/UVOT Upper Limits
DATE:    16/01/22 09:26:13 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (IAA-CSIC/UCL-MSSL) and L. M. Z. Hagen (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160121A
152 s after the BAT trigger (Hagen et al., GCN Circ. 18912).
No optical afterglow consistent with the optical position
reported by MOA (Oates et al., GCN Circ. 18917) is detected
in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

u_FC               152          401          246         >19.7
v                  435          830           78         >18.6
u                  152          918          356         >19.9
w1                 484          754           58         >18.3
m2                 459          854           78         >18.4
w2                 410          805           78         >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.53 in the direction of the burst
(Schlafly and Finkbeiner 2011).


GRB_name: GRB160121A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18923
SUBJECT: GRB 160121A: Swift-XRT refined Analysis
DATE:    16/01/22 13:31:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. D'Avanzo (INAF-OAB), T.G.R. Roegiers (PSU), L.M. McCauley (PSU),
J.A. Kennea (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester),
A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA)
and L.M.Z. Hagen report on behalf of the Swift-XRT team:

We have analysed 7.7 ks of XRT data for GRB 160121A (Hagen et al. GCN
Circ. 18912), from 75 s to 46.0 ks after the  BAT trigger. The data
comprise 80 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN Circ. 18918).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.9 (+0.8, -0.4). At T+209 s  the decay
flattens to an alpha of 0.31 (+/-0.07) before breaking again at T+20.7
ks to a final decay with index alpha=2.1 (+1.6, -1.2).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.00 (+0.24, -0.18). The
best-fitting absorption column is  5.8 (+1.6, -0.5) x 10^21 cm^-2,
consistent with the Galactic value of 5.3 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.2 x 10^-11 (7.0 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.8 (+1.6, -0.5) x 10^21 cm^-2
Galactic foreground: 5.3 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.00 (+0.24, -0.18)

If the light curve continues to decay with a power-law decay index of
2.1, the count rate at T+24 hours will be 3.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x
10^-13 (2.1 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00671231.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160121A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18924
SUBJECT: GRB 160121A: RATIR Optical Observations
DATE:    16/01/22 18:19:22 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:

We observed the field of GRB 160121A (Hagen et al., GCN Circular 18912)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astronmico Nacional on Sierra San Pedro Mrtir from 2016/01 22.13 to
2016/01 22.29 UTC (13.28 to 17.14 hours after the BAT trigger),
obtaining a total of 2.92 hours exposure in the r, i, and z bands.

We detect a source at 07:16:21.16 -23:35:31.5 J2000 (0.5 arcsec),
consistent with the enhanced Swift-XRT position (Osborne et al., GCN
Circular 18918). In comparison with the USNO-B1 and 2MASS catalogs, we
obtain the following magnitudes and 3-sigma upper limits:

   r = 21.73  0.13
   i = 21.10  0.08
   z > 19.80

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

Our observations have almost the same midpoint as the GROND observations
reported by Delvaux et al. (GCN Circular 18921). The i band observations
are consistent, but our r band measurement is surprisingly 0.6 mag
fainter than theirs.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB160121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18925
SUBJECT: GRB 160121A: redshift from the 10.4m GTC
DATE:    16/01/22 22:08:42 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>

R. Sanchez-Ramirez, S. R. Oates, J. C. Tello (IAA-CSIC Granada), S. Geier
(GRANTECAN), P. Tristam (Mt. John Univ. Observatory) and A. J.
Castro-Tirado (IAA-CSIC and ISA-UMA) report on behalf of a larger
collaboration:

We observed the field of GRB 160121A (Hagen  et al. GCN 18912) with the
10.4m GTC telescope (+OSIRIS) at La Palma. 6x900s spectra were taken at
the position of the optical afterglow, detected by the 1.8m MOA (Oates et
al. GCNC 18917), starting at 22:30 UT (i.e. 8.7 h post-burst). We identify
Mg II and several Fe-II absorption lines at z = 1.960 which we propose to
be the host galaxy redshift. An intervening system at z = 1.645 is also
detected.


GRB_name: GRB160123A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18926
SUBJECT: GRB 160123A: Swift detection of a burst
DATE:    16/01/23 09:18:57 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

D. Malesani (DARK/NBI), S. D. Barthelmy (GSFC), T. Sakamoto (AGU) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:

At 08:58:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160123A (trigger=671447).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 150.286, -33.779 which is 
   RA(J2000) = 10h 01m 09s
   Dec(J2000) = -33d 46' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked 
structure with a duration of about 25 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 08:59:38.1 UT, 78.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 150.3125, -33.7754
which is equivalent to:
   RA(J2000)  = 10h 01m 14.99s
   Dec(J2000) = -33d 46' 31.3"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 80 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.31 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.9
(+2.66/-2.30) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
295 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the
XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The
8'x8' region for the list of sources generated on-board covers 100% of the XRT
error circle. The list of sources is typically complete to about 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.10. 

Burst Advocate for this burst is D. Malesani (malesani AT dark-cosmology.dk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160123A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18927
SUBJECT: GRB 160123A: Enhanced Swift-XRT position
DATE:    16/01/23 12:14:56 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1168 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 160123A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 150.31272, -33.77522 which is equivalent
to:

RA (J2000): 10h 01m 15.05s
Dec (J2000): -33d 46' 30.8"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160123A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18928
SUBJECT: GRB 160123A: LCOGT-SSO optical upper limit
DATE:    16/01/23 16:38:07 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Y.-D. Hu (IAA-CSIC), D. Xu (NAOC/CAS), Y. Qing (Geneva Observatory), 
Y.-H. Han (NAOC/CAS, HUST) report:

We observed the field of GRB 160123A (Malesani et al., GCN 18926) using 
the LCOGT-1m located at the Siding Spring Observatory. We obtained 
20x150s R-band images, starting at 12:04:41 UT on 2016-01-23, i.e., 
3.106 hr after the burst.

No optical source is detected at the enhanced XRT position of this GRB 
(Beardmore et al., GCN 18927), down to a limiting magnitude of R~21.0 
mag, calibrated with nearby USNO B1 stars.


GRB_name: GRB160123A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18929
SUBJECT: GRB 160123A: Swift-BAT refined analysis
DATE:    16/01/23 18:39:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. Malesani (DARK/NBI), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 160123A (trigger #671447)
(Malesani, et al., GCN Circ. 18926).  The BAT ground-calculated position is
RA, Dec = 150.277, -33.790 deg, which is 
   RA(J2000)  =  10h 01m 06.4s 
   Dec(J2000) = -33d 47' 23.1" 
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 68%.
 
The mask-weighted light curve shows one peak starting at ~T-15 sec, 
peaking at ~T+0.5 sec, and ending at ~T+10 sec.
T90 (15-350 keV) is 3.95 +- 0.62 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.05 to T+3.00 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.51 +- 0.16.  The fluence in the 15-150 keV band is 3.5 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.01 sec in the 15-150 keV band
is 1.3 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/671447/BA/


GRB_name: GRB160123A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18930
SUBJECT: GRB 160123A: Swift-XRT refined Analysis
DATE:    16/01/23 20:04:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU),
C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U.
Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli 
(INAF-IASFPA) and D. Malesani report on behalf of the Swift-XRT team:

We have analysed 10.0 ks of XRT data for GRB 160123A (Malesani et al.
GCN Circ. 18926), from 64 s to 24.2 ks after the  BAT trigger. The data
comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Beardmore et al. (GCN Circ.
18927).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.72 (+/-0.05).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.09 (+0.28, -0.26). The
best-fitting absorption column is  2.6 (+1.2, -1.0) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (5.2 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.6 (+1.2, -1.0) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 2.2 sigma
Photon index:      2.09 (+0.28, -0.26)

If the light curve continues to decay with a power-law decay index of
0.72, the count rate at T+24 hours will be 3.6 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (1.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00671447.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160123A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18931
SUBJECT: GRB 160123A: Swift/UVOT Upper Limits
DATE:    16/01/23 21:44:10 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and D. Malesani (DARK/NBI)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160123A
82 s after the BAT trigger (Malesani et al., GCN Circ. 18926).
No optical afterglow consistent with the XRT position (Beardmore et al.
GCN Circ. 18927) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            82          231          147         >20.7
u_FC               296          545          246         >19.9
white               82         1196         1041         >21.8
v                  626        11136         1191         >20.3
b                  551        17792         1337         >21.4
u                  296        17792         1563         >20.4
w1                 675        12760         1152         >19.2
m2                 650        12040         1160         >20.0
w2                 601         6977          471         >21.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.10 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160123A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18932
SUBJECT: GRB 160123A: NOT J-band observations
DATE:    16/01/24 02:59:39 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

Daniele Malesani (DARK/NBI), Anlaug Amanda Djupvik (NOT), Tom Reynolds 
(NOT and Tuorla Obs.), and Pall Jakobsson (Univ. Iceland) report on 
behalf of a larger collaboration:

We observed the field of GRB 160123A (Malesani et al., GCN 18926) with 
the Nordic Optical Telescope (NOT) equipped with the NOTCam 
near-infrared camera. Observations were carried out in the J filter. Sky 
conditions were not optimal, with moonlit clouds and a seeing of 1.7". 
Three sets of nine images by 1 minute each were acquired, starting on 
Jan 24.067 UT (16.6 hr after the GRB).

After stacking the best 18 images, no source is detected within the XRT 
localization area (Beardmore et al., GCN 18927; see also 
http://www.swift.ac.uk/xrt_positions/00671447/), down to a limiting 
magnitude J > 19.5 (Vega), calibrated against the 2MASS catalog.


GRB_name: GRB160121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18933
SUBJECT: GRB 160121A: TSHAO optical observation
DATE:    16/01/24 21:29:54 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Kusakin 
(Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) 
report on behalf of a larger GRB follow-up collaboration:

We observed the field of the Swift GRB 160121A (Hagen  et al., GCN 
18912) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical 
Observatory starting on Jan. 22 (UT) 16:17:07.  We obtained several 
images in R filter. We do not detect afterglow  (Oates et al., GCN 
18917; Mazaeva et al., GCN 18920) in a combined image. Preliminary upper 
limit is following

Date       UT start    t-T0     Filter  Exp.    OT     UL (3 sigma)
                        (mid, days)      (s)

2015-01-22 16:17:07    1.13572  R       30*180  n/d    21.2


The photometry is based on nearby USNO-B1.0 stars (see GCN 18920).


GRB_name: GRB160118A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18934
SUBJECT: GRB 160118A CALET Gamma-Ray Burst Monitor detection
DATE:    16/01/25 00:16:44 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
K. Senuma, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), 
S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 160118A (Fermi-GBM trigger #474773146; INTEGRAL-ACS trigger #7343) 
triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 01:25:56.90 on 18 January 2016.  
The burst signal was detected by all instruments.  

The light curve of the SGM shows a several spikes.  The emission starts at T0-20 sec, 
peaks at T0+5 sec and ends at T0+80 sec.   The T90 duration measured by the SGM data 
is 31.0 s $B!^(B 1.4 sec (40-230 keV). 

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.


GRB_name: GRB160121A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18935
SUBJECT: GRB 160121A: RATIR Optical Observations
DATE:    16/01/25 18:37:38 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:

We observed the field of GRB 160121A (Hagen et al., GCN Circular 18912)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astronmico Nacional on Sierra San Pedro Mrtir from 2016/01 24.13 to
2016/01 24.42 UTC (61.29 to 68.12 hours after the BAT trigger),
obtaining a total of 4.27 hours exposure in the r, i and z bands.

We no longer detect the source previously reported by Watson et al.
(GCN Circular 18924). In comparison with the USNO-B1 and 2MASS catalogs,
we obtain the following 3-sigma upper limits:

   r > 22.97
   i > 22.94
   z > 20.10

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB160123A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18936
SUBJECT: GRB 160123A: GROND Upper limits
DATE:    16/01/26 12:50:15 GMT
FROM:    John Graham at MPE/Garching  <graham@mpe.mpg.de>

J. F. Graham, T. Schweyer, and J. Greiner (all MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 160123A (Swift trigger 671447; Malesani, et al., GCN # 18926) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).

Observations started at  04:02 UT on 25 Jan 2016, approximately 43 hours after the GRB trigger, and lasted for 2 hours. They were performed at an average seeing of 1.64" and at an average airmass of 1.06.

We do not detect a source within the Swift-XRT error circle reported by Beardmore et al. (GCN # 18927) down to (AB magnitudes)

g' > 24.1 mag,
r' > 24.4 mag,
i' > 24.0 mag,
z' > 23.9 mag,
J > 21.3 mag,
H > 20.9 mag, and
K > 20.1 mag.

The given limits are derived based on calibrating the images against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.10 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB160127A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18938
SUBJECT: GRB 160127A: Swift detection of a burst with an optical counterpart
DATE:    16/01/27 09:05:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Amaral-Rogers (U Leicester), A. P. Beardmore (U Leicester),
P.A. Evans (U Leicester), A. Y. Lien (GSFC/UMBC),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 08:43:07 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160127A (trigger=671828).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 225.956, +0.089 which is 
   RA(J2000) = 15h 03m 49s
   Dec(J2000) = +00d 05' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~800 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 08:44:25.9 UT, 78.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 225.98136, 0.07222 which is equivalent
to:
   RA(J2000)  = 15h 03m 55.53s
   Dec(J2000) = +00d 04' 20.0"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 109 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.71
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 81 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
  RA(J2000)  = 15:03:55.70 = 225.98209
  DEC(J2000) = +00:04:23.0  = 0.07305
with a 90%-confidence error radius of about 1.10 arc sec. This position is 3.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.13. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.06. 

Burst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160127A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18939
SUBJECT: GRB 160127A: TAROT La Silla observatory optical light curve
DATE:    16/01/27 12:14:43 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Bardho O. (UNS-CNRS-OCA),
Gendre B. (Etelman Observatory-UVI),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 160127A detected by SWIFT
(trigger 671828) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 25.1s after the GRB trigger
(13.4s after the notice). The elevation of the field
increased from 42 degrees above horizon and weather
conditions were good.

We detected the candidate couterpart mentioned by
Amaral-Rogers et al. (GCNC 18938).

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We detect the OT increasing its optical flux from
t0+25s to t0+45s (R~16.9) and fading until the end of
the trail at t0+85s.

Following images were acquired in tracking mode:
t1(s) t2(s)  Rmag   d_Rmag
   99  129    17.9    0.6
  141  171    17.4    0.1
  182  212    17.1    0.7
  223  253    17.1    0.0
  306  396    17.1    0.2
  407  497    17.4    0.4
  610  700    17.6    0.1
  711  801    17.6    0.2
  914 1004    17.6    0.1
1015 1105    17.4    0.0
1742 1922   >18.4    0.6

Magnitudes were estimated with the stars:
NOMAD1 0900-0248256 ra=225.9885561 dec=+00.0840197 R=14.83
NOMAD2 0901-0246538 ra=225.9533572 dec=+00.1320336 R=14.83

Magnitudes are not corrected for galactic dust extinction.

After the first deacay observed in the trailed image from
t0+45s to t0+85s, we observed a bump (maximum flux at t0+220s
R~17.1) and we suspect a second bump (maximum flux at t0+1100s
R~17.3) followed by a steep decay. The OT become fainter
than 18.4 after t0+2000s.


GRB_name: GRB160127A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18940
SUBJECT: GRB 160127A: Enhanced Swift-XRT position
DATE:    16/01/27 12:39:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1815 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160127A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 225.98206, +0.07291 which is equivalent
to:

RA (J2000): 15h 03m 55.69s
Dec (J2000): +00d 04' 22.5"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160127A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18941
SUBJECT: GRB 160127A: RATIR Optical Observations
DATE:    16/01/27 15:16:55 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Antonino Cucchiara (GSFC/STScI), Nat Butler (ASU), Alan M. Watson
(UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom
(UCB), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM),
JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:

We observed the field of GRB 160127A (Amaral-Rogers et al., GCN 18938)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2016/01 27.39 to
2016/01 27.55 UTC (0.73 to 4.43 hours after the BAT trigger), obtaining
a total of 2.68 hours exposure in the r,i and z bands.

We detect the optical counterpart at

RA, Dec = 15:3:55.77, +00:04:22.4 (J2000, +/-0.5â€).

In comparison with the SDSS DR9, we obtain the following magnitudes:

 r 20.64 +/- 0.03
 i 20.66 +/- 0.03
 z 20.14 +/- 0.32

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

Further observations are planned.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro 
MÃ¡rtir.


GRB_name: GRB160123A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18942
SUBJECT: GRB 160123A: TAROT La Silla observatory optical observations
DATE:    16/01/27 15:38:47 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Bardho O. (UNS-CNRS-OCA),
Gendre B. (Etelman Observatory-UVI),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 160123A detected by SWIFT
(trigger 671447) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 33.1s after the GRB trigger
(14.2s after the notice). The elevation of the field
decreased from 59 degrees above horizon and weather
conditions were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+33.1s to t0+93.1s : R > 17.3

The second image is 30.0s exposure in tracking mode:
t0+108.7s to t0+138.7s : R > 18.1

We co-added a series of exposures:
t0+108.7s to t0+305.4s : R > 18.8

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB160127A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18943
SUBJECT: GRB 160127A: Swift-XRT refined Analysis
DATE:    16/01/27 18:07:07 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), A.
D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB),
D.N. Burrows (PSU) and A. Amaral-Rogers report on behalf of the
Swift-XRT team:

We have analysed 6.9 ks of XRT data for GRB 160127A (Amaral-Rogers et
al. GCN Circ. 18938), from 65 s to 19.1 ks after the  BAT trigger. The
data comprise 121 s in Windowed Timing (WT) mode (the first 5 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by Evans
et al. (GCN Circ. 18940).

The late-time light curve (from T0+6.0 ks) can be modelled with a
power-law decay with a decay index of alpha=1.6 (+/-0.3).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.65 (+0.23, -0.21). The
best-fitting absorption column is  1.7 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 5.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.85 (+/-0.15) and a
best-fitting absorption column of 9.7 (+4.4, -3.9) x 10^20 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.6 x 10^-11 (4.2 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.7 (+4.4, -3.9) x 10^20 cm^-2
Galactic foreground: 5.7 x 10^20 cm^-2
Excess significance: 1.7 sigma
Photon index:      1.85 (+/-0.15)

If the light curve continues to decay with a power-law decay index of
1.6, the count rate at T+24 hours will be 1.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.2 x
10^-14 (7.3 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00671828.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160127A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18944
SUBJECT: GRB 160127A: Swift-BAT refined analysis
DATE:    16/01/27 18:48:10 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), A. Amaral-Rogers (U Leicester),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160127A (trigger #671828)
(Amaral-Rogers et al., GCN Circ. 18938).  The BAT ground-calculated position is
RA, Dec = 225.966, 0.080 deg which is
  RA(J2000)  =  15h 03m 51.8s
  Dec(J2000) = +00d 04' 46.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.

The mask-weighted light curve shows a double-peaked structure that starts
at ~ T-1 s and ends at ~ T+6 s. The two peaks occur at ~ T+1 and ~T+3 s,
respectively. T90 (15-350 keV) is 6.16 +- 0.94 sec (estimated error including
systematics).

The time-averaged spectrum from T-1.44 to T+5.70 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.99 +- 1.11,
and Epeak of 25.6 +- 0.0 keV (chi squared 44.15 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.5 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+3.34 sec in the 15-150 keV band is
1.4 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.43 +- 0.23 (chi squared 50.23 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/671828/BA/


GRB_name: GRB160127A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18945
SUBJECT: GRB 160127A: Swift/UVOT Detection
DATE:    16/01/27 20:48:49 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and Amaral-Rogers (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160127A
82 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 18938).
A fading source consistent with the XRT position
(Evans et al. GCN Circ. 18940)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  15:03:55.76 = 225.98234 (deg.)
   Dec (J2000) = +00:04:22.5  =   0.07291 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white (fc)          82          232          147         17.59 +/- 0.04
white              574         2411          342         18.66 +/- 0.08
white             6837         7037          196         20.85 +/- 0.28
v                  624         1942          156         18.46 +/- 0.19
b                  550         1174           58         18.58 +/- 0.16
u (fc)             295          545          246         17.25 +/- 0.05
u                  698         2362          174         18.31 +/- 0.13
u                 6427        19117         1004         20.92 +/- 0.31
w1                 674         1124           58         17.87 +/- 0.20
m2                 824         1966          117         19.07 +/- 0.32
w2                 600         1917          136         19.56 +/- 0.32

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160127A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18946
SUBJECT: GRB 160127A: LCOGT-Sutherland optical upper limit
DATE:    16/01/28 05:58:41 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC/CAS), Y.-H. Han (NAOC/CAS, HUST), Y.-D. Hu (IAA-CSIC), Y. 
Qing (Geneva Observatory) report on behalf of a larger collaboration:

We observed the field of GRB 160127A (Amaral-Rogers et al., GCN 18938) 
using the LCOGT-1m located at the Sutherland, South Africa. Observations 
started at 01:14:53 UT on 2016-01-28 (i.e., 16.53 hr after the burst) 
and a series of 120s Sloan r-band frames were obtained.

The previously reported afterglow (Amaral-Rogers et al., GCN 18938; 
Klotz et al., GCN 18939; Cucchiara et al., GCN 18941) is not detected in 
our stacked image, down to a limiting magnitude of m(r) ~20.5, 
calibrated with the SDSS field.


GRB_name: GRB160127A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18947
SUBJECT: GRB 160127A: VLA Detection
DATE:    16/01/29 02:54:28 GMT
FROM:    Kate Alexander at Harvard  <kalexander@cfa.harvard.edu>

K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger
(Harvard) report on behalf of a larger collaboration:

We observed GRB 160127A (Amaral-Rogers et al., GCN 18938) at multiple
frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2016
January 28.46 UT (1.09 days after the burst). At a mean frequency of 21.8
GHz, we detect a radio source with a preliminary flux density of ~70 uJy at

RA = 15:03:55.773 +/- 0.013
Dec = +00:04:22.07 +/- 0.17

consistent with the enhanced Swift/XRT position (Evans et al., GCN 18940)
and the optical position (Cucchiara et al., GCN 18941; Siegel &
Amaral-Rogers, GCN 18945). Follow-up observations are planned.

We thank the VLA staff for rapidly executing these observations.


GRB_name: GRB160127A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18948
SUBJECT: GRB 160127A: MITSuME Akeno optical upper limits 
DATE:    16/01/29 08:23:14 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

Y.Saito, T.Fujiwara, T. Yoshii, Y. Tano, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160127A (A. Amaral-Rogers et al., GCN Circular #18938) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-01-27 17:04:39 UT (~8.4 h after the burst).
We did not find previously reported afterglow (A. Amaral-Rogers et al., GCN Circular #18938; 
A. Klotz et al., GCN Circular #18939; A. Cucchiara et al., GCN Circular #18941) in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]   g'          Rc          Ic
-----------------------------------------------------------------------------
10.19        18:54:38      11700      > 20.7     > 20.4     > 19.2
-----------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB160127A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18949
SUBJECT: GRB 160127A: Khureltogot optical observations
DATE:    16/01/29 11:37:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), S. Schmalz (AIP), A. Volnova (IKI),  N. Tungalag 
(Research Center of Astronomy and Geophysics MAS),   I. Molotov (KIAM), 
  A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 160127A (Amaral-Rogers et al., GCN 
18938) with ORI-40 telescope of Khureltogot observatory starting on 
Jan., 27 (UT) 19:32:48.  We marginally detect optical afterglow 
(Amaral-Rogers et al., GCN 18938; Klotz et al., GCN 18939; Cucchiara et 
al., GCN 18941). Preliminary photometry of the afterglow is following


Date UT start       t-T0   Filter Exp.   OT   Err   UL(3sigma)
                     (mid, days)   (s)

2016-01-27 19:32:48 0.48499 none  90*60 21.0  0.35  21.0
2016-01-27 21:10:18 0.55333 none  89*60 n/d   n/d   21.2

Photometry is based on nearby SDSS stars, R magnitude deduced from 
Lupton's transformations.

SDSS_DR9_id         R(Lupton)
J150358.16+000929.4 16.36
J150406.02+000738.4 16.03
J150341.40+000835.8 15.17
J150334.55+000806.9 16.20
J150334.11+000513.3 17.32


GRB_name: GRB160127A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18950
SUBJECT: GRB 160127A: RATIR Optical Observations
DATE:    16/01/29 16:56:34 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU),
Enrico Ramirez-Ruiz (UCSC), JosÃ© A. de Diego (UNAM), Leonid Georgiev
(UNAM), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil
Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach 
Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160127A (Amaral-Rogers et al., GCN Circular
18938) with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2016/01 29.43 to
2016/01 29.55 UTC (49.72 to 52.43 hours after the BAT trigger),
obtaining a total of 1.48 hours exposure in the r, i, and z bands.

We no longer detect the optical counterpart reported by Amaral-Rogers et
al. (GCN Circular 18938), Klotz et al. (GCN Circular 18939), Cucchiara
et al. (GCN Circular 18941), and Siegel et al. (GCN Circular 18945). In
comparison with the SDSS DR9 catalog, we obtain the following 3-sigma
upper limits:

 r > 23.15
 i > 23.09
 z > 20.00

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro 
MÃ¡rtir.


GRB_name: GRB160131A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18951
SUBJECT: GRB 160131A: Swift detection of a burst with an optical counterpart
DATE:    16/01/31 08:32:26 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

K. L. Page (U Leicester) and S. D. Barthelmy (GSFC) report on behalf
of the Swift Team:

At 08:20:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160131A (trigger=672236).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 78.182, -7.067 which is 
   RA(J2000)  =  05h 12m 44s
   Dec(J2000) = -07d 04' 02"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a large FRED-like peak
structure with a duration of about 100 sec.  The peak count rate
was ~8100 counts/sec (15-350 keV), at ~16 sec after the trigger. 

The XRT began observing the field at 08:21:41.6 UT, 69.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 78.1700, -7.0489 which is equivalent to:
   RA(J2000)  = +05h 12m 40.80s
   Dec(J2000) = -07d 02' 56.0"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 77 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 1.29e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 78 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 05:12:40.34 =  78.16810
  DEC(J2000) = -07:02:59.1  =  -7.04975
with a 90%-confidence error radius of about 0.61 arc sec. This position is 7.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
13.88 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.11. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18953
SUBJECT: GRB 160131A: LCOGT-FTN optical afterglow observations
DATE:    16/01/31 10:50:40 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi, S. Dichiara (U. Ferrara), S. Kobayashi (LJMU), A. Gomboc 
(U. Nova Gorica), C.G. Mundell (U. Bath), on behalf of a larger 
collaboration report:

The 2-m LCOGT Faulkes Telescope North began observing Swift GRB160131A 
(Page et al. GCN 18951) on Jan 31 at 09:37 UT (~77 minutes after the 
burst trigger) with griZY filters. We clearly detect the optical 
afterglow (Page et al. GCN 18951; Yurkov et al. GCN 18952), with a 
magnitude of r=15.29 +- 0.01 at 81 minutes post GRB, as calibrated 
against nearby USNOB-1 star RA(J2000)=05:12:41.5 DEC(2000)=-07:03:09.81 
with R2=14.28. Observations are going on.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18954
SUBJECT: GRB160131A:  Xinglong TNT optical observation
DATE:    16/01/31 11:02:19 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin,   X. F. Wang,  J. Y. Wei,  Y. L. Qiu,  J. S. Deng,  X. M. Meng
D. Xu, J. Wang,  X. H. Han and C. Wu on behalf of EAFON report:

We  observed  GRB 160131A (Page et al. GCN 18951)  with
Xinglong  0.8-m TNT telescope at 10:22:09UT,  about 2 hours after the burst.
The optical afterglow (Page et a.., GCN 18951, YurKov et al., GCN 18952)
 was  detected in our white, B, and R, I-band images. 
The brightness of the optical afterglow is about 16.1 mag
at the mid time  of 118 min afer the burst,  calibrated by 
the USNO B1.0 star (RA=05:12:39.8  DEC=-7:02:02  R2=15.51mag).
 
The message may be cited.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18955
SUBJECT: GRB 160131A: Xinglong 60cm WFT optical observation
DATE:    16/01/31 12:19:37 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin,  X. M. Meng,  Y. J. Xiao,  J. Y. Wei,  E. W. Liang,  X. G. Wang, 
Y. G. Yang, X. M. Lu, L. Huang,  X. H. Han ,  H. B. Cai,  Y. L. Qiu, 
J. Wang,  C. Wu,  J. S. Deng, H. L. Li and D. Xu  report:

We  observed  GRB 160131A (Page et al. GCN 18951)  with
60cm WFT telescope at 10:29:14UT,  about 127 min after the burst.
The optical afterglow (Page et a.., GCN 18951, YurKov et al., GCN 18952,
Guidorzi et al., GCN 18953,  Xin et al., 18954) was  detected 
in our white and R-band  images.  The brightness of the optical afterglow 
is about 15.85 mag at the mid time  of 127.5 min afer the burst,  calibrated by 
the USNO B1.0 star (RA=05:12:39.8  DEC=-7:02:02  R2=15.51mag).
 
Observations are continuing

The message may be cited.


GRB_name: GRB160131A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18956
SUBJECT: GRB 160131A: RATIR Optical Observations
DATE:    16/01/31 13:36:58 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM),
JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:

We observed the field of GRB 160131A (Page et al., GCN Circular 18951)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2016/01 31.35 to
2016/01 31.37 UTC (0.07 to 0.50 hours after the BAT trigger), obtaining
a total of 0.18 hours exposure in the r, i, and z bands.

We detect a bright uncatalogued source at 05:12:40.33 -07:03:00 (J2000,
Â±0.5 arcsec). In comparison with the USNO-B1 catalog, we obtain the
following mean magnitudes:

 r = 13.35 Â± 0.04
 i = 13.01 Â± 0.02
 z = 12.67 Â± 0.04

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

The source fades roughly as t^-0.87 during our observations. This source
is presumably the optical counterpart reported by Page et al. (GCN
Circular 18951), Yurkov et al. (GCN Circular 18952), Guidorzi et al.
(GCN Circular 18953), and Xin et al. (GCN Circular 18954).

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18957
SUBJECT: GRB 160131A: LCOGT-SSO optical observations
DATE:    16/01/31 14:28:09 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC/CAS), Y.-H. Han (NAOC/CAS, HUST), Y.-D. Hu (IAA-CSIC), Y.
Qing (Geneva Observatory), L.-P. Xin (NAOC/CAS) report on behalf of a 
larger collaboration:

We observed the field of GRB 160131A (Page & Barthelmy, GCN 18951) using 
the LCOGT-1m located at the Siding Spring Observatory. Observations 
started at 11:50:49 UT and ended at 12:15:46 UT on 2016-01-31 (i.e., 
3.505 - 3.921 hr after the BAT trigger) and a series of 150s 
U-/B-/V-/R-/I-band frames were obtained.

The afterglow of the burst (e.g., Page & Barthelmy, GCN 18951; Yurkov et 
al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 1894,18955; 
Watson et al., GCN 18956) is detected in our individual image in each 
band. Preliminary analysis gives rise to the following magnitudes:

m(I) = 16.05 +/- 0.02
m(R) = 16.56 +/- 0.02
m(V) = 17.07 +/- 0.02
m(B) = 17.59 +/- 0.02

calibrated with four SDSS stars in the field.


GRB_name: GRB160131A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18958
SUBJECT: GRB 160131A: Enhanced Swift-XRT position
DATE:    16/01/31 16:23:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2574 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 160131A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 78.16795, -7.04988 which is equivalent
to:

RA (J2000): 05h 12m 40.31s
Dec (J2000): -07d 02' 59.6"

with an uncertainty of 2.2 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160131A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18959
SUBJECT: GRB 160131A: Swift-BAT refined analysis
DATE:    16/01/31 19:00:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 160131A (trigger #672236)
(Page, et al., GCN Circ. 18951).  The BAT ground-calculated position is
RA, Dec = 78.170, -7.037 deg, which is 
   RA(J2000)  =  05h 12m 40.8s 
   Dec(J2000) = -07d 02' 13.0" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
 
The mask-weighted light curves shows a small precursor starting at ~T-2 sec
and the main peak is a FRED starting at ~T+10 sec, peaking at ~T+18 sec, and returning
to baseline at ~T+800 sec (although there is a possibility that it goes longer
but the observing window ended at T+950 sec).
T90 (15-350 keV) is 325 +- 72 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.49 to T+773.03 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.24 +- 0.05.  The fluence in the 15-150 keV band is 2.04 +- 0.05 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+15.97 sec in the 15-150 keV band
is 6.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/672236/BA/


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18960
SUBJECT: GRB 160131A: iTelescope optical observations
DATE:    16/01/31 19:52:46 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:

We have detected GRB 160131A optical afterglow at iTelescope observatory
(Siding Spring, Australia) using T9  0.32-m f/9 RCOS telescope and T17 and 
T32  0.43-m f/6.8 astrographs. The observations were started at 2016-01-31 
10:01:17 (UT). Several images using photometric R and V filters with 300 sec
and 120 sec exposure time were taken.

The afterglow was detected at the position RA 05:12:40.34 and DEC
-07:02:58.3.

The following magnitudes were obtained from the observations using
NOMAD1 0829-0078536 (R=15.390 and V=14.820) as a comparison star:

T32 observations
Tmid(s)+T0    Filter     Exp. time             Mag          Mag. Err.
6197              V          300s                   15.05          0.04
6796              V          300s                   15.17          0.04
7395              V          300s                   15.28          0.04

T17 observations
Tmid(s)+T0    Filter      Exp. time            Mag          Mag. Err.
6651              R           4x300s              15.71          0.02
7946              R           4x300s              15.96          0.02
11649            R           4x300s              16.56          0.03
12952            R           4x300s              16.68          0.03
14244            R           4x300s              16.86          0.04
15709            R           4x300s              16.99          0.04

T9 observations
Tmid(s)+T0    Filter      Exp. time             Mag          Mag. Err.
14761           V            5x120s              16.27          0.34
15454           V            5x120s              16.43          0.37
16190           V            5x120s              16.55          0.42
17083           V            5x120s              16.55          0.44
17767           V            5x120s              16.59          0.43
18452           V            5x120s              16.65          0.48
19179           V            5x120s              16.70          0.54
20295           V            5x120s              16.75          0.56

---
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GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18961
SUBJECT: GRB 160131A: TNG optical observations
DATE:    16/01/31 20:10:52 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, P. D'Avanzo (INAF/OAB), V. D'Elia (INAF/OAR and ASI/ASDC), L. Di Fabrizio, G. Mainella (INAF/TNG) report on behalf of the CIBO collaboration:

We observed the field of GRB 160131A (Page et al., GCN 18951) with the 3.6m TNG telescope equipped with the DOLoRes camera in imaging mode. Observations started on 2016 Jan 31 at 19:52 UT and consisted of two images (120s each) obtained with the R filter.

The optical afterglow (Page et al., GCN 18951; Yurkov et al. GCN 18952; Guidorzi et al. GCN 18953; Xin et al., GCN 18954, GCN 18955; Watson et al. GCN 18956; Xu et al. GCN 18957) is clearly detected. From a preliminary analysis, we estimate a magnitude of R=18.1 +/- 0.1, calibrated against the USNO-B1 catalogue.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18962
SUBJECT: GRB 160131A: Khureltogot optical observations
DATE:    16/01/31 20:22:21 GMT
FROM:    Alexei Pozanenko at IKI  <alex@grb.rssi.ru>

E. Mazaeva (IKI), S. Schmalz (AIP),  N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 160131A (Page et al., GCN Page) with ORI-40 telescope of Khureltogot observatory  on Jan., 31 from(UT)  11:14 up to (UT) 16:34. We obtained several unfilteed images.
We clearly detect optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., GCN 18955; Watson et al., GCN 18956). Preliminary photometry of the afterglow in the first images is following


Date        UT start t-T0 Filter Exp. OT Err 
                    (mid, days) (s)

                                                                             
2016-01-31  11:14:41 0.12106     20   16.43      0.10
2016-01-31  11:27:26 0.13015     60   16.49      0.04
2016-01-31  11:28:30 0.13089     60   16.51      0.04
2016-01-31  11:29:35 0.13164     60   16.50      0.04
2016-01-31  11:30:39 0.13238     60   16.52      0.05
2016-01-31  11:31:43 0.13388     60   16.61      0.05
2016-01-31  11:33:52 0.13462     60   16.46      0.04
2016-01-31  11:34:57 0.13537     60   16.53      0.05
2016-01-31  11:36:01 0.13611     60   16.58      0.05
2016-01-31  11:37:06 0.13686     60   16.62      0.05
2016-01-31  11:38:10 0.13760     60   16.56      0.04
2016-01-31  11:39:14 0.13834     60   16.58      0.04
2016-01-31  11:40:18 0.13909     60   16.57      0.04

Photometry is based on nearby USNO B1.0 stars, R2 magnitude.


GRB_name: GRB160131A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18963
SUBJECT: GRB 160131A: Swift-XRT refined Analysis
DATE:    16/01/31 20:32:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows
(PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU) and K.L. Page report
on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 160131A (Page et al. GCN
Circ. 18951), from 60 s to 23.6 ks after the  BAT trigger. The data
comprise 523 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 18958).

The late-time light curve (from T0+3.8 ks) can be modelled with a
power-law decay with a decay index of alpha=1.09 (+/-0.05).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.44 (+/-0.03). The
best-fitting absorption column is  1.76 (+/-0.15) x 10^21 cm^-2, in
excess of the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.10 (+/-0.08) and a
best-fitting absorption column of 2.56 (+0.31, -0.29) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.4 x 10^-11 (5.2 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.56 (+0.31, -0.29) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: 7.9 sigma
Photon index:      2.10 (+/-0.08)

If the light curve continues to decay with a power-law decay index of
1.09, the count rate at T+24 hours will be 0.053 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x
10^-12 (2.8 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00672236.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18964
SUBJECT: GRB 160131A: Bassano Bresciano Observatory optical observations
DATE:    16/01/31 20:48:03 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs  <oabb@ulisse.bs.it>

U.Quadri, L.Strabla and R.Girelli report:

We imaged the field of GRB 160131A (Page et al., GCN Circular 18951)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy (member of ISSP:Italian Supernovae Search Project)

The observations started 9.18 hour after the GRB trigger, at the end of 
twilight, with our Newton telescope D=250 mm F/D=4.8

Initially weather conditions were good, but then the fog has 
forbidden the observations.

We co-added 2 series of 10 exposures of 60 sec each: 
Start T0 + 9.18 hour. End T0+ 9.87 hour  

We clearly detect the optical counterpart (Page et al., GCN 18951; 
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953;Xin et al.,
GCN 18954; Xin et al., GCN 18955; Watson et al., GCN 18956). 
at the following coordinates:

05h 12m 40.37s -07d 02m 58.9s  +/-2 arcsec

Photometry was performed using comparison stars with UCAC4 catalog.
in CV (clear + Jhonson V) and CR (Clear + Jhonson R) magnitudes, 
and are not corrected for galactic dust extinction:

------------------------------------
      JD         Mag    Filter   SNR
------------------------------------ 
2457419.24025   17.360   CR    14.34 
2457419.26062   17.241   CR     9.74 
                                  
2457419.24025   17.671   CV    14.40 
2457419.26062   17.498   CV     9.74 
-------------------------------------


The images are available at:
http://www.osservatoriobassano.org/GRB.asp

The message may be cited.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18965
SUBJECT: GRB 160131A: TNG spectroscopic observations and redshift
DATE:    16/01/31 22:10:53 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

D. Malesani (DARK/NBI), V. D'Elia (INAF/OAR and ASI/ASDC), P. D'Avanzo, A. Melandri (INAF-OAB), L. A. Antonelli (INAF/OAR and ASI/ASDC), L. Di Fabrizio, G. Mainella (INAF/TNG) report on behalf of the CIBO collaboration:

Following the observations reported in Melandri et al. (GCN 18961), we carried out further observations of the optical afterglow of GRB 160131A (Page et al., GCN 18951) with the 3.6m TNG telescope equipped with the DOLoRes camera in spectroscopic mode. A spectrum was acquired with the LR-B grism covering the range between 3500 and 8000 AA. The observation consisted of a single 1200 s exposure, starting on 2016 Jan 31 at 20:12 UT.

A preliminary analysis of the spectrum (based on archival calibration files) shows clearly the continuum with several absorption features due to Fe II, Mg II and Mg I at a common redshift of 0.97, which we propose as the redshift of the GRB.


We acknowledge support from the TNG visiting astronomer Ennio Poretti.


GRB_name: GRB160131A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18966
SUBJECT: GRB 160131A: GTC spectroscopy of the afterglow
DATE:    16/01/31 23:49:42 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC), 
R. Sanchez-Ramirez (IAA-CSIC), Gabriel Gomez Velarde (GRANTECAN) and
Victor Herrera (GRANTECAN) report on behalf of a larger collaboration:

We observed the afterglow of GRB 160131A (Page et al. GCN 18951) with 
the 10.4 m GTC equipped with OSIRIS. Observations consisted of 3x600s 
spectra with grism R1000B (covering from 3700 to 7800 AA) and 3x600s 
with grism R1000R (covering from 5100 to 10000 AA). The first spectrum 
started at 21:52 UT (13.53 hr after the GRB onset) under very bad seeing 
conditions (> 3").

In spite of the poor seeing we detect a strong continuum across the complete
range with multiple absorption features of FeII, NiII, MnII, MgII, MgI, and CaII 
at a common redshift of 0.972, consistent with the value measured by 
Malesani et al. from TNG (GCN 18965).

[GCN OPS NOTE(04feb16): Per author's request, GGV and VH were added 
to the author list.]


GRB_name: GRB160131A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18967
SUBJECT: GRB 160131A: GROND Detection of the Optical/NIR Afterglow
DATE:    16/02/01 01:20:14 GMT
FROM:    Fabian Knust at MPE/GROND  <fknust@mpe.mpg.de>

F. Knust, J. Bolmer, J. Greiner (all MPE Garching), and D. A. Kann,  (TLS
Tautenburg) report on behalf of the GROND team:

We observed the field of GRB 160131A (Swift trigger 672236; Page et al.,
GCN #18951) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at  0:44 UT on 2016-02-01, 16 hrs after the GRB
trigger, and are continuing. They were performed at an average seeing of
1.3" and at an average airmass of 1.1.

We found a single point source within the 2.2" Swift-XRT error circle
reported by Goad et al. (GCN #18958), in agreement with the UVOT afterglow
 (Page et al., GCN #18951) at

RA (J2000) = 05 h 12 m 40.32 s
Dec. (J2000) = -07d 02' 58.92

with an uncertainty of 0.5" in each coordinate.

Based on the first 4.40 min of total exposures in g'r'i'z' and 4.0 min in
JHK, we estimate preliminary magnitudes (all in AB system) of

g' = 18.7 +/- 0.05 mag,
r' = 18.4 +/- 0.05 mag,
i' = 18.3 +/- 0.05 mag,
z' = 18.2 +/- 0.05 mag,
J  = 17.7 +/- 0.1 mag,
H  = 17.6 +/- 0.1 mag, and
K  = 17.1 +/- 0.1 mag.

Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.09 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB160131A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18968
SUBJECT: GRB 160131A: MITSuME Ishigakijima Optical Observation
DATE:    16/02/01 02:05:16 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda (OAO, NAOJ),  H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:

We observed the field of GRB 160131A (Pagani and Barthelmy, GCNC 18951)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

The observation started on 2016-01-31 14:06:17 UT (~5.8 h afterthe burst).
We detected the previously reported afterglow (Pagani and Barthelmy, GCNC 18951;
Yurkov et al., GCNC 18952; Guidorzi et al., GCNC 18953) in all the three bands.

Photometric results of the OT are listed below.
We used GSC2.3 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'   g'_err  Rc   Rc_err  Ic   Ic_err
-----------------------------------------------------------------------
0.24373    14:11:29     540.0    17.92 0.09   17.19 0.05   16.88 0.06
-----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18969
SUBJECT: GRB 160131A: Xinglong/BFOSC spectroscopy
DATE:    16/02/01 03:38:02 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu, L.-P. Xin, J. Wang (NAOC/CAS) report on behalf of a larger 
collaboration:

We observed the optical afterglow of GRB 160131A (e.g., Page et al., GCN 
18951; Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., 
GCN 18954) using the 2.16m telescope located at Xinglong, Heibei, China, 
equipped with the BFOSC camera. A 2400s spectrum was acquired with the 
G4+385LP grism covering the range of 3500 - 8500 AA, starting at 
13:49:08 UT on 2016-01-31.

The spectrum shows a continuum across the whole range, superimposed with 
absorption features of Mg II, Ca II H+K at a common redshift of 0.97, 
being consistent with measurements by Malesani et al. (GCN 18965) and de 
Ugarte Postigo et al. (GCN 18966).

We thank the excellent support of the Xinlong 2.16m staff, in particular 
Meng Zhai and Junjun Jia.


GRB_name: GRB160131A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18970
SUBJECT: GRB 160131A Swift/UVOT Detection
DATE:    16/02/01 18:09:05 GMT
FROM:    Marissa McCaule at PSU  <marissamc@swift.psu.edu>

L. M. McCauley (PSU), K. L. Page (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160131A
78 s after the BAT trigger (Page et al., GCN Circ. 18951).
A fading source consistent with the XRT position (Beardmore et al. GCN
Circ. 18159)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:12:40.33 =  78.16804 (deg.)
    Dec (J2000) = -07:02:58.81  =  -7.04967 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early
exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white_fc              78         228         147          13.77+-1.10
white               5051       11361        1081          16.71+-0.02
v                   4026        5662         393          15.72+-0.03
b                   4846       10449        1138          16.81+-0.02
u                    290         540         245          13.08+-0.03
u                   4641        6277         393          15.64+-0.03
uvw1                4436        6072         393          16.18+-0.04
uvm2                4231        5867         393          16.64+-0.06
uvw2                3821       12083        1098          17.43+-0.05




The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.11 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18971
SUBJECT: GRB 160131A: Mondy optical observations
DATE:    16/02/01 19:53:38 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), E. Klunko (ISTP), A. Volnova (IKI), I. Korobtsev 
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the Swift GRB 160131A (Page et al., GCN 18951) with AZT-33IK 
telescope of Sayan observatory (Mondy)  starting on Feb.01 (UT) 
13:01:56. We clearly detect optical afterglow (Page et al., GCN 18951; 
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 
18954; Xin et al., GCN 18955; Watson et al., GCN 18956). Preliminary 
photometry of the afterglow of the first image is following


Date        UT start   t-T0    Filter   Exp.   OT     Err.
                       (mid, days)       (s)


2016-02-01  13:01:56  1.19543  R        1*120  19.40  0.08


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18972
SUBJECT: GRB 160131A: AbAO optical observations
DATE:    16/02/01 20:28:41 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), R. Inasaridze (AbAO), V. Ayvazian (AbAO), A. Volnova 
(IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger 
GRB follow-up collaboration:

We observed the field of Swift GRB 160131A (Page et al., GCN 18951) with 
AS-32 (0.7m) telescope of Abastumani Observatory starting on Jan. 31 
(UT) 19:16:57. We obtained several unfiltered images of 120 s exposure. 
We detect optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 
18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., 
GCN 18955; Watson et al., GCN 18956). Preliminary light curve can be 
found in http://grb.rssi.ru/GRB160131A/GRB160131A_20160131_AbAO_lc.png

The photometry is base on nearby USNO-B1.0 stars:

USNO-B.1_id  R2
0829-0078223 15.70
0829-0078147 14.56
0828-0074893 14.88
0828-0074768 14.81


GRB_name: GRB160131A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18973
SUBJECT: GRB 160131A: Optical observations from T150 OSN
DATE:    16/02/02 15:12:35 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
V. Casanova (IAA-CSIC) and F. Aceituno (IAA-CSIC) report:

We observed the afterglow of GRB 160131A (Page et al. GCN 18951) 
from the 1.5m telescope (T150), at Sierra Nevada Observatory (Granada, 
Spain) in two epochs on the first and second night after the GRB.

In the first epoch we performed observations in the V, R and I filters 
and the object is well detected in all bands. During these observations
on January 31.807 (10.8 hr after the burst), the object has a magnitude of
R=17.90+/-0.02 (Vega), using as reference star the same 
USNO-B1.0 object mentioned in the circular by Xin et al. (GCN 18954).

On the second night we performed photometry in 5 bands, U, B, V, R 
and I, the object is again detected in all bands. In an image with mean 
epoch February 1.835 (35.5 hr after the burst) we detect the object at 
R=19.83+/-0.03.


GRB_name: GRB160131A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18974
SUBJECT: Konus-Wind observation of GRB 160131A
DATE:    16/02/02 15:36:05 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, extremely hard-spectrum GRB 160131A
(Swift-BAT trigger #672236: Page & Barthelmy, GCN 18951;
Cummings  et al., GCN 18959)
triggered Konus-Wind at T0=30044.577 s UT (08:20:44.577).

The burst light curve shows a single, FRED-like pulse
with a total duration (80-1400 keV) of ~200 s.
In the softest KW energy band the emission can be traced up to ~300 s.
The emission is seen up to ~15 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.26(-0.32,+0.31)x10^-4 erg/cm2,
and a 64-ms peak energy flux, measured from T0+2.704 s,
of 2.23(-0.46,+0.46)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+162.048 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.97(-0.15,+0.24),
the high energy photon index beta = -1.56(-0.10,+0.07),
the peak energy Ep = 586(-259,+518) keV,
chi2 = 98/97 dof.

The spectrum near the peak count rate
(measured from T0+0.256 to T0+14.592 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.94(-0.18,+0.13),
the high energy photon index beta = -1.56(-0.56,+0.06),
the peak energy Ep = 1152(-438,+3060) keV,
chi2 = 135/97 dof.

Assuming the redshift z=0.972 (Malesani et al., GCN 18965;
de Ugarte Postigo, Thoene & Sanchez-Ramirez, GCN 18966;
Xu, Xin & Wang, GCN 18969)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~8.3x10^53 erg,
the peak luminosity L_iso is ~1.1x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~1150 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160131_T30044/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160131A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18976
SUBJECT: GRB160131A: NOEMA detection of the millimetre afterglow
DATE:    16/02/02 17:25:19 GMT
FROM:    Steve Schulze at U of Iceland  <sts30@hi.is>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), S. Schulze (PUC, MAS), M. Bremer (IRAM), S. MartÃ­n (JAO), J. M. Winters (IRAM) report on behalf a larger collaboration:

We conduced millimetre observations of GRB160131A (Page et al., GCN 18951) with the NOrthern Extended Millimeter Array (NOEMA; Plateau de Bure, France) at 93 and 150 GHz. Observations started at 17:05 UT on February 1 (i.e. 1.36 days after the burst).

We clearly detect the afterglow at both frequencies. A preliminary analysis of the 93 GHz data reveals a flux density of 1.94 +/- 0.07 mJy. Further observations are scheduled.

We encourage follow-up observations at all frequencies.


GRB_name: GRB160131A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18977
SUBJECT: GRB 160131A: VLA detection
DATE:    16/02/02 21:22:19 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley), K. D. Alexander, and E. Berger (Harvard)
report on behalf of a larger collaboration:

"We observed GRB 160131A (Page & Barthelmy; GCN 18951) at multiple
frequencies with the Karl G. Jansky Very Large Array (VLA) beginning on
2016 February 01.11 UT (0.76 days after the burst). At a mean frequency of
21.8 GHz, we detect a radio source with a preliminary flux density of ~
0.53 mJy at

RA = 15:12:40.351 +/- 0.001
Dec = -07:02:58.80 +/- 0.02

consistent with the enhanced Swift/XRT position (Goad et al.; GCN 18958)
and the optical position (Page & Barthelmy.; GCN 18951, Yurkov et al.; GCN
18952). Follow-up observations are planned. We thank the VLA staff for
rapidly scheduling these observations."


GRB_name: GRB160131A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18978
SUBJECT: GRB 160131A: correction to VLA position
DATE:    16/02/02 22:20:06 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley) reports:

"Our original circular (Laskar et al.; GCN 18977) contained a typo in the
right ascension of the radio source. The correct position is

RA = 05:12:40.351 +/- 0.001
Dec = -07:02:58.80 +/- 0.02

Thanks to Frank Marshall for pointing out the error."


GRB_name: GRB160203A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18979
SUBJECT: GRB 160203A: Swift detection of a burst
DATE:    16/02/03 02:34:26 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

P. D'Avanzo (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 02:13:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160203A (trigger=672525).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 161.952, -24.762, which is 
   RA(J2000)  =  10h 47m 48s
   Dec(J2000) = -24d 45' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several overlapping peaks
with a duration of about 25 sec.  The peak count rate
was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 02:15:27.8 UT, 137.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 161.9511,
-24.7887 which is equivalent to:
   RA(J2000)  = 10h 47m 48.27s
   Dec(J2000) = -24d 47' 19.2"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 96 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 7.41
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 139 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.07. 

Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160203A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18980
SUBJECT: GRB 160203A: GROND Afterglow Candidate
DATE:    16/02/03 02:44:04 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

T. Kruehler (MPE Garching), D. A. Kann (TLS Tautenburg), J. Greiner (MPE
Garching), and J. Bolmer (MPE Garching) report on behalf of the GROND
team:

We observed the field of GRB 160203A (Swift trigger 672525; D'Avanzo et
al., GCN #18979) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 02:18:58 UT on 2016-02-03, 6 min after the GRB
trigger, and are continuing. They were performed at an average seeing of
1".2 and at an average airmass of 1.8.

We found a single point source within the 2".3 Swift-XRT error circle at

RA (J2000) = 10:47:48.35
Dec. (J2000) = -24:47:19.8

with an uncertainty of 0".5 in each coordinate.

Based on the first 4.40 min of total exposures in g'r'i'z' and 4.0 min in
JHK at a mid-time of 02:22:14, we estimate preliminary magnitudes (all in
AB system) of

g' = 18.9 +/- 0.1 mag,
r' = 18.0 +/- 0.1 mag,
i' = 17.7 +/- 0.1 mag,
z' = 17.6 +/- 0.1 mag,
J  = 17.0 +/- 0.1 mag, and
H  = 16.7 +/- 0.1 mag.

While we cannot establish fading yet, we propose this source to be the
afterglow of GRB 160203A.

Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V) = 0.06 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB160203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18981
SUBJECT: GRB 160203A: LCOGT-Cerro Tololo optical afterglow confirmation
DATE:    16/02/03 03:44:40 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC/CAS) reports on behalf of a large collaboration:

We observed the field of GRB 160203A (D'Avanzo et al., GCN 18979) using 
the LCOGT-1m located at Cerro Tololo. Observations started at 02:35:09 
UT on 2016-02-03 (i.e., 1319 s after the BAT trigger) and 10x150s R-band 
frames were obtained.

We detect an uncatalogued and decaying source at the position reported 
by Kruehler et al. (GCN 18980), which has m(R)= 18.04 in the first 150s 
exposure, calibrated with the nearby USNN star, #0651-0249724 
(R1=R2=16.84 mag). The fading nature confirms the source is the 
afterglow of GRB 160203A.


GRB_name: GRB160203A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18982
SUBJECT: The bright GRB160203A: X-shooter spectroscopy and redshift 
DATE:    16/02/03 04:22:29 GMT
FROM:    Giovanna Pugliese at API/UvA  <pugliese@astroduo.org>

G. Pugliese (API/UvA), S. Covino (INAF/OAB), T. Kruehler (MPE Garching), D. Xu (NAOC/CAS), 
N. R. Tanvir (Leicester), report on behalf of a larger collaboration:

We observed the afterglow of GRB 160203A (D'Avanzo et al., GCN 18979;
Kruehler et al., GCN 18980; Xu, GCN 18981) with ESO's Very Large
Telescope UT2 equipped with X-shooter. Our observations were performed
in Rapid Response Mode and started at 02:31:35 UT on 03-02-2016, just about 
18 min after the Swift trigger. The X-shooter spectra cover the range between 
3000 and 23000 AA, and were obtained at a seeing of around 0.8".

A preliminary analysis of the spectrum shows a clear continuum with
absorption features due to Lyman-alpha and various metal lines (SII 1254, SiII 1259/60, OI 1302, 
SiII 1304, CII 1334, Si IV 1393/1402, SiII 1526, CIV 1548/1550, FeII 1608, AlII 1670) at a common 
redshift of 3.52, which we propose as the redshift of the GRB. 
We also detect an intervening system at z=2.203.

We acknowledge the fast and efficient support provided by Paranal staff. In particular we thank Dimitri 
Gadotti, Boris Haeussler, and Marcela Espinoza for their excellent job. 


GRB_name: GRB160203A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18983
SUBJECT: GRB 160203A: Enhanced Swift-XRT position
DATE:    16/02/03 06:07:19 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 310 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160203A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 161.95125, -24.78914 which is equivalent
to:

RA (J2000): 10h 47m 48.30s
Dec (J2000): -24d 47' 20.9"

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160203A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18984
SUBJECT: GRB 160203A: Swift/UVOT Detection
DATE:    16/02/03 12:50:43 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and P. D'Avanzo (INAF-OAB) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160203A 
151 s after the BAT trigger (D'Avanzo et al., GCN Circ. 18979).
A fading source consistent with the optical position (Kruehler et al. 
GCN Circ. 18980) is detected in the initial UVOT exposures in the white 
filter.

Preliminary detections and 3-sigma upper limits using the UVOT 
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for 
the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white_FC           151          301          147         20.56 Â± 0.3
white            10022        10928          885         21.9 Â± 0.3
b                 4946         5146          197        >20.7
u                  309          472          160        >19.5
v                 5562         5762          197        >19.7
uvw1              5972         6171          197        >19.7
uvm2              5766         5966          197        >19.6
uvw2              5357         5557          197        >19.9

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.07 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB160203A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18985
SUBJECT: GRB 160203A: TAROT La Silla - TAROT Calern - Zadko observations
DATE:    16/02/03 14:39:31 GMT
FROM:    Michel Boer at Obs Haute Prov.  <michel@boer.science>

Boer, M., Laugier, R. (CNRS-ARTEMIS), Klotz A., Turpin D., Atteia J.L. 
(CNRS-OMP-IRAP), Gendre B. (UVI - Etelman Obs.), Coward, D. McPherson, 
D. Williams A., Martin R., Moore J., Dodson R. (UWA) report:

The position of GRB 160203A (d'Avanzo et al., GCNC 18979) was observed 
with TAROT-Calern (TCA France), TAROT-Chile (TCH), and Zadko (W. 
Australia). Observing conditions where good for TCH and Zadko, with 
absorption for TCA.
The observations have started at
TCH: 2:16:24.7 UT, T0+3m14s
TCA: 2:16:28 UT, T0+ 3m18
Zadko: 13:04:33 UT, T0+10h52m

No source has been detected at the position of the reported afterglow 
(GCNC 18980, 18981, 18982, 18984). R limiting magnitude are 16.3 for 
TCA, 17.2 for TCH and 19.5 for Zadko.
At the time of writing Zadko is still observing the source position.

This notice is citable.


GRB_name: GRB160203A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18986
SUBJECT: GRB 160203A: Swift-XRT refined Analysis
DATE:    16/02/03 14:42:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), T.G.R. Roegiers (PSU), L.M. McCauley
(PSU), J.A. Kennea (PSU), C. Pagani (U. Leicester) and P. D'Avanzo
report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 160203A (D'Avanzo et al. GCN
Circ. 18979), from 122 s to 33.8 ks after the  BAT trigger. The data
comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Osborne et al. (GCN Circ.
18983).

The late-time light curve (from T0+4.9 ks) can be modelled with a
power-law decay with a decay index of alpha=1.15 (+0.24, -0.23).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.76 (+0.23, -0.22). The
best-fitting absorption column is  1.5 (+2.6, -1.5) x 10^22 cm^-2, at a
redshift of 3.52, in addition to the Galactic value of 7.4 x 10^20
cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum  is 3.8 x
10^-11 (4.5 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 7.4 x 10^20 cm^-2
Intrinsic column:    1.5 (+2.6, -1.5) x 10^22 cm^-2 at z=3.52
Photon index:      1.76 (+0.23, -0.22)

If the light curve continues to decay with a power-law decay index of
1.15, the count rate at T+24 hours will be 2.8 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.2 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00672525.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18987
SUBJECT: GRB 160203A: Skynet PROMPT-CTIO observations of the optical afterglow
DATE:    16/02/03 18:50:26 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter@physics.unc.edu>

A. Trotter, D. Reichart, J. Haislip, J. Moore, N. Frank, M. Maples, E. Johnson, R. Joyner, J. Martin, C. Salemi, J. A. Crain, K. Ivarsen, A. LaCluyze, and M. Nysewander report:

Skynet observed the Swift BAT/XRT localization of GRB 160203A (D'Avanzo et al., GCN 18979, Swift trigger=672525) with with one 16" telescope (P5) and two 24" telescopes (P1 and P8) of the PROMPT array at CTIO, Chile. Starting at 2016-02-03 02:17:18 UT and continuing until 09:26 UT (t=4.1m-7.2h post-trigger), Skynet took a total of 353 exposures ranging from 20-160s. Between t=4.1m and t=61m, both P5 and P8 observed in the I band. Between t=78m and t=7.2h, P1 cycled through the V, R and I filters, while P8 cycled through the B, V and R filters.

We clearly detect an optical afterglow at the position first reported by Kruehler et al. (GCN 18980). The OT exhibits a rising light curve at early times, peaking at I~17 at t~8m, and fades thereafter, with I~20 at t~5h.

A preliminary light curve is at:
http://www.skynet.unc.edu/grb/grb160203a.png

Magnitudes are in the Vega System, calibrated to 8 APASS DR9 stars in the field.  Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.06 (Schlafly & Finkbeiner 2011).

No further Skynet observations are scheduled.


GRB_name: GRB160131A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18988
SUBJECT: GRB 160131A: RATIR Optical Observations
DATE:    16/02/04 16:54:53 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM),
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160131A (Page, et al., GCN 18951) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/02 4.10 to 2016/02 4.36 UTC (89.96 to
96.25 hours after the BAT trigger), obtaining a total of 4.60 hours
exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle (Osborne, et al., GCN
18958), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following detections and upper limit (3-sigma):

  r = 21.64 +/- 0.05
  i = 21.41 +/- 0.03
  z > 20.48

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  We note that there is a faint,
possible source present in the DSS near this source which could be the GRB
host galaxy.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160203A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18989
SUBJECT: GRB 160203A: RATIR Optical Observations
DATE:    16/02/04 16:56:05 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM),
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160203A (D'Avanzo, et al., GCN 18979) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/02 4.36 to 2016/02 4.55 UTC (30.42 to
34.94 hours after the BAT trigger), obtaining a total of 3.27 hours
exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle (Osborne, et al., GCN
18983), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following detections and upper limit (3-sigma):

  r = 23.35 +/- 0.21
  i = 22.90 +/- 0.13
  z > 20.55

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18990
SUBJECT: GRB 160203A: TSHAO optical observations
DATE:    16/02/05 13:54:34 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), E. Mazaeva (IKI),  A. Kusakin (Fesenkov Astrophysical 
Institute),  A. Pozanenko (IKI) report on behalf of a larger GRB 
follow-up collaboration:

We observed the field of the Swift GRB 160203A (D'Avanzo et al., GCN 
18979) with Zeiss-1000 (West) 1-m telescope of Tien Shan Astronomical 
Observatory starting on Feb. 03 (UT) 20:31:45.  We obtained several 
images in R filter. We marginally (S/N ~ 2) detect afterglow  (Kruehler 
et al., GCN 18980) in a combined image. Preliminary photometry of the 
afterglow is following

Date       UT start    t-T0     Filter  Exp.    OT    Err
                        (mid, days)      (s)

2016-02-03 20:31:45    0.80045  R       21*300 23.0   0.5


The photometry is based on nearby USNO-B1.0 stars:

USNO-B1.0_id   R2
0652-0250834   18.04
0651-0249689   18.51


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18991
SUBJECT: GRB 160131A: Mondy optcial observations
DATE:    16/02/05 15:15:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), E. Mazaeva (IKI), E. Klunko (ISTP),  I. Korobtsev 
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the Swift GRB 160131A (Page et al., GCN 18951) with AZT-33IK 
telescope of Sayan observatory (Mondy)  starting on Feb.04 (UT) 
11:42:43. We detect optical afterglow (Page et al., GCN 18951; Yurkov et 
al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin 
et al., GCN 18955; Watson et al., GCN 18956) in a combined image. 
Preliminary photometry is following


Date        UT start   t-T0    Filter   Exp.   OT     Err.
                       (mid, days)       (s)


2016-02-04  11:42:43  4.16058  R       29*120  21.70  0.23

USNO-B.1_id     R2

0829-0078147    14.56
0829-0078222    18.96
0829-0078226    18.69
0829-0078129    17.62


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18992
SUBJECT: GRB 160131A: TSHAO optical observations
DATE:    16/02/05 18:49:47 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova 
(IKI), A. Kusakin (Fesenkov Astrophysical Institute),  A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the Swift GRB 160131A (Page et al., GCN 18951) with 
Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory 
starting on Feb. 05 (UT) 14:22:45.  We obtained several images in R 
filter. We clearly detect optical afterglow (Page et al., GCN 18951; 
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 
18954; Xin et al., GCN 18955; Watson et al., GCN 18956) in a combined 
image. Preliminary photometry is following


Date        UT start   t-T0    Filter   Exp.   OT     Err.
                       (mid, days)       (s)


2016-02-05  14:22:45   5.28802 R       21*300  22.40  0.20

Photometry is based on nearby USNO-B1.0 stars

USNO-B.1_id  R2

0829-0078223 15.70
0829-0078147 14.56
0829-0078167 17.71
0829-0078222 18.96
0829-0078226 18.69
0829-0078129 17.62


GRB_name: GRB160206A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18993
SUBJECT: GRB 160206A: MAXI/GSC detection
DATE:    16/02/06 07:01:50 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko@crab.riken.jp>

K. Furuya (Miyazaki U.) , Nakahira, M.(JAXA), M. Nakajima (Nihon U.), M. Serino (RIKEN),
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. E. Nakagawa (JAXA),
T. Mihara, M. Sugizaki, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), 
N. Kawai, M. Arimoto, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech),
A. Yoshida, T. Sakamoto, H. Ohtsuki Y. Kawakubo (AGU),
H. Tsunemi, R. Imatani (Osaka U.),
H. Negoro (Nihon U.), K. Tanaka, T. Masumitsu (Nihon U.),
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.),
Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.),
M. Yamauchi, D. Itoh, (Miyazaki U.)
K. Yamaoka (Nagoya U.),
M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient 
source at 02:52:43 UT on on 2016 Feburary 6.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (132.696 deg, -36.099 deg) = (08 50 47, -36 05 56) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.33 deg and 0.3 deg, respectively.
The roll angle of long axis from the north direction is 23.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 125 +- 26 mCrab
(4-10keV, 1 sigma error).
Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (132.055 deg, -35.576 deg) = (08 48 13, -35 34 32) (J2000)
(R.A., Dec) = (132.787 deg, -35.291 deg) = (08 51 08, -35 17 28) (J2000)
(R.A., Dec) = (133.399 deg, -36.778 deg) = (08 53 35, -36 46 40) (J2000)
(R.A., Dec) = (132.642 deg, -37.044 deg) = (08 50 34, -37 02 39) (J2000)
There was no significant excess flux in the previous transit at UT 01:20
and in the next transit at 04:25 UT with an upper limit of 20 mCrab for each.


GRB_name: GRB160206A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18994
SUBJECT: GRB 160206A: Tiled Swift observations
DATE:    16/02/06 15:44:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 160206A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00053

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160206B
Detection_method: iPTF
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18995
SUBJECT: GRB 160206B: iPTF P48 Observations and Optical Transient Candidates 
DATE:    16/02/06 18:02:12 GMT
FROM:    Leo Singer at GSFC/iPTF  <leo.p.singer@nasa.gov>

L. P. Singer (NASA/GSFC), S. B. Cenko (NASA/GSFC), M. M. Kasliwal
(Caltech), and V. Bhalerao (IUCAA) report on behalf of a larger
collaboration:

Fermi GBM detected GRB 160206B (trigger 476446756 / bn160206430) at
2016-02-06 10:19:12.43. At 10:29:40, about 10 minutes after the burst, we
began searching for optical counterparts using the Palomar 48-inch Oschin
telescope (P48).

We imaged 114 fields covering an area of 379 deg^2 and covering most of
the 2-sigma statistical+systematic region of the final Fermi GBM
localization. We estimate a 84% prior probability that these fields
contain the true location of the source. Sifting through candidate
variable sources using image subtraction and standard iPTF vetting
procedures, we detected the following optical transient candidates:

   name       RA        Dec      mag   t    Notes
----------------------------------------------------------------------------
                   Hosts with spectroscopic redshifts
----------------------------------------------------------------------------
iPTF16ca 181.162415 +45.059301 19.97 +2.39 z=0.190, host is an X-ray source
iPTF16ce 188.768138 +47.301857 20.27 +2.81 z=0.131
iPTF16ch 189.333005 +51.432720 20.70 +1.82 z=0.120
iPTF16cc 187.973175 +45.076476 19.12 +2.73 z=0.062, poor subtraction in interacting host galaxy
iPTF16cl 170.605169 +59.384422 20.12 +1.79 z=0.051
iPTF16cd 187.947490 +47.927964 19.48 +1.39 z=0.030
----------------------------------------------------------------------------
                    Hosts with photometric redshifts
----------------------------------------------------------------------------
iPTF16cg 175.872772 +50.316844 19.65 +2.30 z=0.31
iPTF16ci 180.780807 +53.977868 19.49 +1.73 z=0.27
iPTF16ck 193.756732 +57.354180 20.42 +2.93 z=0.19
iPTF16cf 197.002541 +48.632699 20.05 +2.08 z=0.13
iPTF16bx 116.788070 +22.170396 19.20 -1.32 z=0.09

Times are in hours since the GBM trigger. Magnitudes are in the Mould R
filter and in the AB system, calibrated with respect to point sources in
SDSS as described in Ofek et al. (2012, http://dx.doi.org/10.1086/664065).

Further observations of the above candidates are encouraged to determine
their nature and if one of them is the optical afterglow of the GRB. We
have scheduled additional imaging of the P48 fields tonight.

The diagram http://asd.gsfc.nasa.gov/Brad.Cenko/Fermi476446756.pdf
shows the locations of our candidates and the P48 fields in relation to
the Fermi GBM 1-, 2-, and 3-sigma statistical+systematic contours.


GRB_name: GRB160206A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18996
SUBJECT: GRB 160206A: Swift-XRT observations
DATE:    16/02/06 23:26:02 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Maselli  (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), C. Pagani (U. Leicester), A.P. Beardmore (U.
Leicester) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 160206A (Furuya et al. GCN Circ. 18993) in a series of
observations tiled on the sky. The total exposure time is 3.7 ks,
distributed over 4 tiles; the maximum exposure at a single sky location
was 1.6 ks. The data were collected between T0+46.2 ks and T0+53.5 ks,
and are entirely in Photon Counting (PC) mode. 

Two uncatalogued X-ray sources have been detected, however none of them
is above the RASS limit or shows definitive signs of fading. Therefore,
at the present time we cannot identify which, if any, is the afterglow.
Details of these sources are given below:

Source 1:
  RA (J2000):  132.7319  =  08:50:55.65
  Dec (J2000): -36.3302  =  -36:19:48.5
  Error: 4.1 arcsec (radius, 90% conf.)
  Count-rate: 0.0262 +/- 0.0060 ct s^-1
  Flux: (5.8 +/- 1.3)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000):  132.5583  =  08:50:13.98
  Dec (J2000): -36.0137  =  -36:00:49.5
  Error: 5.8 arcsec (radius, 90% conf.)
  Count-rate: (5.2 +/- 2.4)e-3 ct s^-1
  Flux: (1.04 +/- 0.49)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00053.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160206A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18997
SUBJECT: GRB 160206A: GROND Observations
DATE:    16/02/07 13:20:51 GMT
FROM:    Corentin Delvaux at MPE  <delvaux@mpe.mpg.de>

T. Kruehler, C. Delvaux , J. Greiner (all MPE Garching) report on behalf
of the GROND team:

We observed the field of GRB 160206A (Furuya et al., GCN #18993)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory
(Chile).

Observations centered on XRT source #2 (Page et al. 2016, GCN #18996)
started at 00:40 UT on 2016-02-07, 22.3 hrs after the GRB trigger. They
were performed at an average seeing of 1.5" and at an average airmass of
1.4.

We detect no source brighter than the Digitized Sky Survey limiting
magnitudes in the 5.8" Swift-XRT error circle. There is one fainter source
(r'~22.6 AB mag) at RA(2000.0) = 08:50:14.1, Decl.(2000.0) = -36:00:52,
but no statement about variability  can be made at this stage.


GRB_name: GRB160203A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18998
SUBJECT: GRB 160203A: Swift-BAT refined analysis
DATE:    16/02/07 15:41:25 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), P. D'Avanzo (INAF-OAB),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 160203A (trigger #672525)
(D'Avanzo, et al., GCN Circ. 18979).  The BAT ground-calculated position is
RA, Dec = 161.967, -24.772 deg, which is 
   RA(J2000)  =  10h 47m 52.2s 
   Dec(J2000) = -24d 46' 17.9" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 20%.
 
The mask-weighted light curve shows a single peak starting at ~T-1 sec,
peaking at ~T+13 sec, and ending at ~T+40 sec.  T90 (15-350 keV) is
20.2 +- 3.2 sec (estimated error including systematics).
 
The time-averaged spectrum from T+1.46 to T+25.78 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.93 +- 0.20.  The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+11.98 sec in the 15-150 keV band
is 1.3 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/672525/BA/


GRB_name: GRB160203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  18999
SUBJECT: GRB 160203A: Zadko observatory - Gingin optical detection
DATE:    16/02/07 18:07:18 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.),
Coward, D. McPherson, D. Williams A., Martin R.,
Moore J., Dodson R. (UWA) report:

We analysed the field of GRB 160203A detected by SWIFT
(trigger 672525) with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.

The observations started 10.9h after the GRB trigger.
The elevation of the field increased from
23 degrees above horizon and weather conditions
were very good.

The first fast analysis (Boer et al. GCNC 18985)
can be now completed by late images. The stack
of images shows the afterglow. Measurements:

t1(s) t2(s)  Rmag   d_Rmag
44824 48920 22.30   0.50

Magnitudes are not corrected for galactic dust extinction.


GRB_name: GRB160206A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19000
SUBJECT: GRB 160206A: Swift/UVOT observations
DATE:    16/02/07 20:04:48 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>

M. De Pasquale (PSU) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began observing the field of MAXI-detected GRB
160206A (Furuya et al., GCN Circ. 18993) 46.2 ks after the trigger.

No optical afterglow consistent with the XRT source 2 given by Page
et al. (GCN Circ. 18996) is detected in the UVOT exposures.

Preliminary 3-sigma upper limit using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed UVOT
exposures is:

Filter         T_start(s)   T_stop(s)      Exp(s)    3sigma UL Mag

u                48081        52769         909           21


Source 1 is found to be consistent with the magnitude 12.3 object
TyC 7149 2271-1.

These magnitudes are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.47 in the direction of the burst
(Schlegel et al. 1998).

[GCN OPS NOTE(08feb16): Per author's request, "XRT source 1"
was changed to "XRT source 2", and "Source 2 is" was changed
to "Source 1 is".]


GRB_name: GRB151215A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19001
SUBJECT: GRB 151215A: TAROT Calern observatory very early optical detection
DATE:    16/02/07 22:36:40 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 151215A detected by SWIFT
(trigger 667392) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 31.6s after the GRB trigger
(17.7s after the notice). The elevation of the field decreased
from 56 degrees above horizon and weather conditions
were good but images were slightly unfocused.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
Due to the unfocused condition, we took time to
reprocess the image to extract the magnitude of the
optical transient discovered by Cenko et al. (GCNC 18692):

t1(s) t2(s)  Rmag   d_Rmag
31.6  44.5  17.3    0.5
44.5  91.6  16.7    0.3

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB160203A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19003
SUBJECT: GRB 160203A: MITSuME Akeno optical upper limits
DATE:    16/02/08 08:54:58 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

Y.Ono, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, Y. Yano, S. Kurita, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160203A (P. D'Avanzo et al., GCN Circular #18979) with the 
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-02-03 15:46:41 UT (~13.5 h after the burst).
We did not find any new point source within XRT circle in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT     T-EXP[sec]      g'         Rc          Ic
----------------------------------------------------------------------------
   15.98        18:12:04         10080       >21.0     >20.8    >20.1
----------------------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB160131A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19004
SUBJECT: GRB 160131A: TSHAO optical observations
DATE:    16/02/08 22:04:39 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova 
(IKI), A. Kusakin (Fesenkov Astrophysical Institute),  A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the Swift GRB 160131A (Page et al., GCN 18951) with 
Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory. 
We obtained several images in R filter on Feb. 06 and Feb. 07.The 
optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 18952; 
Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., GCN 
18955; Watson et al., GCN 18956) is detected on Feb. 06 and not detected 
on Feb. 07.  Preliminary photometry is following


Date        UT start   t-T0    Filter  Exp.   OT     Err.
                       (mid, days)     (s)


2016-02-06 13:45:54   6.26762 R       21*300 22.40   0.3
2016-02-07 13:30:04   7.25330 R       21*300 >22.40 (3sigma)


Photometry is based on nearby USNO-B1.0 stars

USNO-B.1_id  R2

0829-0078223 15.70
0829-0078147 14.56
0829-0078167 17.71
0829-0078222 18.96
0829-0078226 18.69
0829-0078129 17.62


GRB_name: GRB160206B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19006
SUBJECT: GRB 160206B: Fermi GBM detection
DATE:    16/02/09 17:07:58 GMT
FROM:    Oliver Roberts at UCD/Fermi  <oliver.roberts@ucd.ie>

O.J. Roberts (UCD) and C. Meegan (UAH) report on
behalf of the Fermi GBM Team:

"At 10:19:12.43 UT on 06 February 2016, the Fermi
Gamma-Ray Burst Monitor triggered and located GRB
160206B (trigger 476446756 / 160206430). A list of
optical candidates were observed by iPTF within the
2-sigma statistical+systematic region of the final
on-ground calculated location (Singer et al., GCN 18995).
The on-ground calculated location, using the GBM trigger
data, is RA = 184.3, DEC = 52.4 (J2000 degrees,
equivalent to 12h 17m, 52d 24'), with an uncertainty of
4.2 degrees (radius, 1-sigma containment, statistical only;
there is additionally a systematic error which we have
characterized as a core-plus-tail model, with 90% of GRBs
having a 3.7 deg error and a small tail suffering a larger
than 10 deg systematic error.
[Connaughton et al. 2015, ApJS, 216, 32]).

The angle from the Fermi LAT boresight is about 83 degrees.

The GBM light curve consists of a FRED-like pulse with a
duration (T90) of about 21.5 s (50-300 keV). The
time-averaged spectrum from T0-4.9 s to T0+16.6 s is best
fit by a power law function with an exponential high-energy
cutoff. The power law index is -0.93 +/- 0.10 and the cutoff
energy, parameterized as Epeak, is 356.0 +/- 69.5 keV.

The event fluence (10-1000 keV) in this time interval is
(4.6 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux
measured starting from T0+3.4 s in the 10-1000 keV band is
3.0 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160203A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19007
SUBJECT: GRB 160203A: RATIR Upper Limits
DATE:    16/02/10 02:40:34 GMT
FROM:    V. Zach Golkhou at ASU/RATIR  <golkhou@gmail.com>

V. Zach Golkhou (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander
Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox
(STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey
Moseley (GSFC), John Capone (UMD), and Vicki Toy (UMD) report:

We observed the field of GRB 160203A (D'Avanzo, et al., GCN 18979) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/02 6.28 to 2016/02 6.52 UTC (76.40 to
82.32 hours after the BAT trigger), obtaining a total of 4.27
hours exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle (Osborne, et al.,
GCN 18983), in comparison with the USNO-B1 and 2MASS catalogs, we obtain
the following upper limits (3-sigma):

r    >  24.20
i    >  24.14
z   >  19.92

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160206A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19008
SUBJECT: GRB 160206A: Kiso/KWFC optical observations
DATE:    16/02/10 04:46:44 GMT
FROM:    Tomoki Morokuma at U of Tokyo  <tmorokuma@ioa.s.u-tokyo.ac.jp>

Tomoki Morokuma (The University of Tokyo), Nozomu Tominaga (Konan
University), Masaomi Tanaka (National Astronomical Observatory of
Japan), Akihiro Suzuki (Kyoto University), Motoko Serino (RIKEN),
Takanori Sakamoto (Aoyama Gakuin University), and Keiichi Maeda (Kyoto
University) report:

We took r-band images for the field of GRB 160206A (Furuya et al. 2016,
GCN Circ. 18993) 10.5 hours after the trigger with the Kiso Wide Field
Camera (KWFC; Sako et al. 2012, SPIE, 8446, 84466L) on the 1.05-m Kiso
Schmidt telescope in Japan. Our data were taken in a very low elevation
(10-15 degrees) and the detection limits were 17.0 mag (S/N=5, without
the Galactic extinction correction). No optical afterglow is detected at
the position of Swift XRT source 2 (Page et al. 2016, GCN Circ. 18996)
in any of our ten 180-sec exposures. The Swift XRT source 1 (TYC
7149-2271-1) is saturated in all the images and it is difficult to
evaluate its time variability.

Starting times (UT) of the exposures are summarized as below.

 date(UT)    time  t_exp[s]
2016-02-06 13:27:19 180
2016-02-06 13:32:51 180
2016-02-06 13:38:17 180
2016-02-06 13:43:43 180
2016-02-06 13:49:06 180
2016-02-06 13:54:36 180
2016-02-06 14:00:01 180
2016-02-06 14:05:26 180
2016-02-06 14:10:50 180
2016-02-06 14:16:17 180


GRB_name: GRB160131A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19009
SUBJECT: Low frequency GMRT observations of GRB 160131A
DATE:    16/02/10 10:15:28 GMT
FROM:    Poonam Chandra at TIFR  <poonam@ncra.tifr.res.in>

Poonam Chandra (NCRA-TIFR)  and A. J. Nayana (NCRA-TIFR) report on 
behalf of a
larger collaboration:

We carried out the Giant Metrewave Radio Telescope (GMRT) observations of
GRB 160131A (GCN Circ. 18951) at 1280 and 610 MHz band on 2016 Feb 09.61 
UT.
The data is badly affected by RFI and hence we could not obtain the 
expected rms.
The 3-sigma upper limit on the GRB flux in the Swift error cicle (GCN 
Circ.  18970)
are  570  and 382 uJy in 1280 and 610 MHz bands, respectively.

The GMRT data for GRB 160131A is public for anyone to use.

Further observations are planned.  We thank GMRT staff for making these 
observations possible.


GRB_name: GRB160131A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19010
SUBJECT: GRB 160131A: second epoch observations with the GMRT
DATE:    16/02/11 10:00:38 GMT
FROM:    Poonam Chandra at TIFR  <poonam@ncra.tifr.res.in>

Poonam Chandra (NCRA-TIFR)  and A. J. Nayana (NCRA-TIFR) report on 
behalf of a
larger collaboration:

We reobserved GRB 160131A (GCN Circ. 18951)  with the Giant Metrewave Radio
Telescope (GMRT) at 1420 MHz band on 2016 Feb 10.78 UT. While we do not 
detect
the GRB radio afterglow, we place very constraining 3-sigma upper limit 
on the
GRB flux in the Swift error cicle (GCN Circ.  18970) to be 105 uJy.

The GMRT data for GRB 160131A is public for anyone to use.

Further observations are planned.  We thank GMRT staff for making these 
observations possible.

-- 
_________________________________________
Poonam Chandra
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Pune University Campus, Ganeshkhind
Pune 411007, Maharashtra, INDIA
Phone: +91 20 2571 9290
Fax:   +91 20 2569 7257
Email: poonam@ncra.tifr.res.in
Web:   www.ncra.tifr.res.in:8081/~poonam/
_________________________________________


GRB_name: GRB160131A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19011
SUBJECT: GRB160131A: detection of polarisation by Astrosat CZTI
DATE:    16/02/12 13:23:06 GMT
FROM:    Dipankar Bhattacharya at IUCAA  <dipankar@iucaa.in>

S. V. Vadawale (PRL), T. Chattopadhyay  (PRL),  N. P. S. Mithun (PRL),
A. R. Rao (TIFR),  D. Bhattacharya (IUCAA), Varun Bhalerao (IUCAA)
report on behalf of the Astrosat CZTI collaboration:

Astrosat CZT Imager detected GRB 160131A (Page and Barthelmy, GCN 18951)
at an incident angle of 63 degrees from the telescope pointing axis.
The T90 was measured to be 106 s and 97 s in 30 - 100 keV and 100 - 300
keV respectively. CZTI being sensitive to polarimetry [Chattopadhyay et
al, 2014, EXPA, Vadawale et al 2015, A&A], we have analysed the double
events due to Compton scattering and detect a clear azimuthal modulation
of 0.30 +/- 0.12 %, with a detection significance of 2.5 sigma. Based on a
preliminary mass modelling, we estimate that the source polarisation
fraction lies between ~ 50 - 60 % in 100-300 keV band.  A detailed mass 
modeling to refine this measurement and its estimated uncertainty is in 
progress.  In an earlier event, GRB 151006A (Bhalerao et al. GCN 18422) 
CZT Imager data showed a marginal evidence for polarisation signal.  From 
the higher detection confidence for this brighter GRB160131A, we estimate 
that CZT Imager can provide time resolved spectro-polarimetry for GRBs 
with fluence larger than 10^-4 erg per cm^2.

This message may be cited.


GRB_name: GRB160216A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19014
SUBJECT: GRB 160216A: Swift detection of a burst
DATE:    16/02/16 19:23:21 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

E. Troja (NASA/GSFC/UMCP), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), S. B. Cenko (GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),
L. M. McCauley (PSU), T. G. R. Roegiers (PSU),
B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf
of the Swift Team:

At 19:10:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160216A (trigger=673978).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 311.706, -71.555 which is 
   RA(J2000)  =  20h 46m 49s
   Dec(J2000) = -71d 33' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several bright peaks
with a duration of about 30 sec.  The peak count rate
was ~7000 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 19:12:05.3 UT, 93.9 seconds after
the BAT trigger. The position determined from promptly downlinked data
differs significantly from the on-board position, suggesting that the
XRT may have centroided on a cosmic ray; the initial XRT position
notice should be treated with caution. Using promptly downlinked data
we find a fading, uncatalogued X-ray source located at RA, Dec
311.68630, -71.54787 which is equivalent to:
   RA(J2000)  = 20h 46m 44.71s
   Dec(J2000) = -71d 32' 52.3"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 34 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (4.50 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.1
(+0.67/-0.50) x 10^22 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 100 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05. 

Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160216A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19015
SUBJECT: GRB 160216A: Enhanced Swift-XRT position
DATE:    16/02/16 23:22:45 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 400 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160216A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 311.68414, -71.54837 which is equivalent
to:

RA (J2000): 20h 46m 44.19s
Dec (J2000): -71d 32' 54.1"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160216A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19016
SUBJECT: GRB 160216A: Swift/UVOT Upper Limits
DATE:    16/02/17 00:04:06 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160216A
101 s after the BAT trigger (Troja et al., GCN Circ. 19014).  No optical
afterglow consistent with the XRT position (Beardmore et al. GCN Circ.
19015) has been detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           101          251          147         >19.8
u_FC               314          564          246         >19.1
white              101         5921          541         >20.6
v                 4695         6301          364         >19.0
b                 4079         5716          393         >19.9
u                  314         5510          442         >19.3
w1                5105         5305          197         >19.4
m2                4900         5099          197         >19.7
w2                4490         6126          393         >20.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160216A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19018
SUBJECT: GRB 160216A: Swift-XRT refined Analysis
DATE:    16/02/17 08:31:13 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), A. Maselli  (INAF-IASFPA), A. Melandri
(INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N.
Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester) and E. Troja report on behalf of the
Swift-XRT team:

We have analysed 7.5 ks of XRT data for GRB 160216A (Troja et al. GCN
Circ. 19014), from 81 s to 34.6 ks after the  BAT trigger. The data
comprise 36 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 19015).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.996 (+0.026, -0.025).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.90 (+0.18, -0.17). The
best-fitting absorption column is  5.4 (+1.2, -1.0) x 10^21 cm^-2, in
excess of the Galactic value of 4.5 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.4 x 10^-11 (6.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.4 (+1.2, -1.0) x 10^21 cm^-2
Galactic foreground: 4.5 x 10^20 cm^-2
Excess significance: 7.8 sigma
Photon index:      1.90 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
0.996, the count rate at T+24 hours will be 0.010 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.4 x
10^-13 (6.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00673978.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160216A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19019
SUBJECT: Konus-Wind observation of GRB 160216A (and GRB 160216B)
DATE:    16/02/17 13:51:14 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team, report:

The long-duration GRB 160216A (Swift-BAT trigger #673978:
Troja et al., GCN Circ. 19014)
triggered Konus-Wind at T0=69030.129 s UT (19:10:30.129).

The burst light curve shows a double-peaked structure
started at ~T0-0.3 s with a total duration (80-1400 keV) of ~3.6 s.
The emission is seen up to ~4 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.05(-0.35,+0.39)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+2.864 s,
of 2.62(-0.70,+0.71)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.66 (-0.31,+0.36)
and Ep = 140 (-18,+25) keV (chi2 = 91/87 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.0
(chi2 = 91/86 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160216_T69030/

Another long-duration GRB 160216B was detected by Konus-Wind
in the same trigger record at ~T0+150 s. This second burst was
also detected by Fermi-GBM, trigger #477342778.The KW ecliptic
latitude response for GRB 160216B is consistent with the GBM
localization and inconsistent with the BAT localization
of GRB 160216A.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160216A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19020
SUBJECT: GRB 160216A: Swift-BAT refined analysis
DATE:    16/02/17 14:12:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 160216A (trigger #673978)
(Troja, et al., GCN Circ. 19014).  The BAT ground-calculated position is
RA, Dec = 311.679, -71.550 deg, which is 
   RA(J2000)  =  20h 46m 43.0s 
   Dec(J2000) = -71d 33' 01.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.
 
The mask-weighted light curve shows a small peak starting at ~T-0.3 sec,
then two large peaks at ~T+0.6 s and ~T+3.2 sec, and ending at ~T+20 sec.
T90 (15-350 keV) is 11.0 +- 1.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.30 to T+11.70 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.48 +- 0.08.  The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.70 sec in the 15-150 keV band
is 7.3 +- 0.5 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/673978/BA/


GRB_name: GRB160220A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19023
SUBJECT: GRB 160220A: Swift detection of a burst
DATE:    16/02/20 01:36:52 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Y. Lien (GSFC/UMBC), P.A. Evans (U Leicester), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 01:25:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160220A (trigger=674670).  Swift could not immediately
slew to the burst. 
The BAT on-board calculated location is 
RA, Dec 236.925, -18.555 which is 
   RA(J2000) = 15h 47m 42s
   Dec(J2000) = -18d 33' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 15 sec.  The peak count rate
was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+50.1
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160220A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19024
SUBJECT: GRB 160220A: Swift-XRT observations
DATE:    16/02/20 03:13:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. Campana (INAF-OAB), G. Cusumano (INAF-IASF PA), P.A. Evans (U.
Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU) and J.A.
Kennea (PSU) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 160220A at 02:19:23.8 UT,
3238.1 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 236.95167,
-18.56501 which is equivalent to:
   RA(J2000)  = 15h 47m 48.40s
   Dec(J2000) = -18d 33' 54.0"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 97 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.09
x 10^21 cm^-2 (Willingale et al. 2013). 


GRB_name: GRB160220A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19025
SUBJECT: GRB 160220A: Enhanced Swift-XRT position
DATE:    16/02/20 07:05:40 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1730 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 160220A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 236.95288, -18.56605 which is equivalent
to:

RA (J2000): 15h 47m 48.69s
Dec (J2000): -18d 33' 57.8"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160220A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19026
SUBJECT: GRB 160220A: Fermi GBM observation
DATE:    16/02/20 07:21:32 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>

C. M. Hui (NASA/MSFC) and E. Burns (UAH)
report on behalf of the Fermi GBM Team:

"At 01:25:26.968 UT on 20 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160220A (trigger 477624330 / 160220059), which
was also detected by the Swift/BAT (Lien et al. 2016, GCN 19023).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 46
degrees.

The GBM light curve shows a single peak
with a duration (T90) of about 9 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+9.216 s is
best fit by a simple power law function with index -1.5 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(1.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.43 s in the 10-1000 keV band
is 1.7 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160220A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19027
SUBJECT: GRB 160220A: GROND Optical/NIR Upper Limits
DATE:    16/02/20 08:06:33 GMT
FROM:    Philip Wiseman at MPE/Swift  <wiseman@mpe.mpg.de>

P. Wiseman, F. Knust, J. Greiner (all MPE Garching) report on behalf of
the GROND team:

We observed the field of GRB 160220A (Swift trigger 674670; Lien et al.,
GCN #19023) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at  05:46 UT on 2016-02-20, 4.5 hrs after the GRB
trigger. They were performed at an average seeing of 1.5" and at an
average airmass of 1.6.

We do not find any single point source within the 1.9" Enhanced Swift-XRT
error circle reported by Evans et al. (GCN #19025). Based on 36.00 min of
total exposures in g'r'i'z' and 30.00 min in JHK, at a mid-time of 06:49
UT, we estimate preliminary upper limiting magnitudes (AB system) of

g' > 23.4 mag,
r' > 23.9 mag,
i' > 23.6 mag,
z' > 23.3 mag,
J  > 21.6 mag,
H  > 20.9 mag, and
K  > 18.0 mag.

Given limits are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.12 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB160220A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19028
SUBJECT: GRB 160220A: MASTER-Amur observations
DATE:    16/02/20 09:39:50 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, 
A.Kuznetsov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

MASTER-SAAO  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB160220A (Lien et al., GCN #19023) 
22 sec after notice time and 65 
sec after trigger time at 2016-02-20 01:26:34 UT. On our first (10s 
exposure)  set we haven't found optical transient  within SWIFT error-box 
(ra=15 47 41 dec=-18 33 16 r=0.050000).
The 5-sigma upper limit has been about 15.5mag
The automatically generated table image limits you can see below:


Pro.ID Pro.type      time      Exp. Limit Filt.   Tube
                        UT        s       mag  polaroid

162238 Alert      01:26:34 10 15.5 P/ EAST
162239 Alert       01:26:34 10      15.5 P\ WEST
162240 Alert      01:26:56 20 14.8 P/ EAST
162241  Alert       01:26:56    20      14.8    P\      WEST
162241  Alert       01:26:56    20      14.8    P\      WEST
162242  Alert       01:27:29    20      16.7    P/      EAST
162243  Alert       01:27:29    20      16.6    P\      WEST
162244  Alert       01:28:02    30      17.9    P/      EAST
162245  Alert       01:28:02    30      17.9    P\      WEST
162246  Alert       01:28:44    40      16.5    P/      EAST
162247  Alert      01:28:44  40  16.4  P\  WEST
162264 SumAlert     01:26:56    70      17.7    P/      EAST
162265 SumAlert     01:26:56    70      17.8    P\      WEST
162266 SumAlert     01:28:44   150      18.2    P/      EAST
162267 SumAlert     01:28:44   150      18.3    P\      WEST
162323 SumAlert     01:26:56   670 19.3 P/ EAST
162321 SumAlert     01:26:56   670 19.1 P\ WEST
........

162338 SumAlert     01:40:23  1800 19.4 P/ EAST
162337 SumAlert     01:40:23  1800  19.2  P\  WEST

The message may be cited.


GRB_name: GRB160220B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19029
SUBJECT: GRB 160220B: Swift detection of a burst
DATE:    16/02/20 11:22:29 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

J. R. Cummings (NASA/UMBC), A. Y. Lien (GSFC/UMBC),
D. Malesani (DARK/NBI) and K. L. Page (U Leicester) report on behalf
of the Swift Team:

At 11:10:53 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160220B (trigger=674734). Swift did not slew immediately
due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 259.854, -18.123 which is 
   RA(J2000) = 17h 19m 25s
   Dec(J2000) = -18d 07' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 30 sec.  The peak count rate
was ~6000 counts/sec (15-350 keV), at ~6 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+46.5
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160220A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19030
SUBJECT: GRB 160220A: TAROT Calern and TAROT La Silla observatory optical observations
DATE:    16/02/20 13:43:43 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 160220A detected by SWIFT
(trigger 674670) with the TAROT robotic telescopes (D=25cm)
located at the Calern observatory, France and
at the European Southern Observatory, La Silla
observatory, Chile.

The observations started 1.64h after the GRB trigger
at Calern and 4.00h after the GRB trigger at la Silla
(the field was not visible at the date of the trigger).
The elevation of the field increased from
20 degrees above horizon and weather conditions
were good.

We co-added a series of exposures. We do not detected the
X-ray couterpart mentioned by Campana et al. (GCNC 19024):

t1(h) t2(h)  Rmag_lim  Site
1.64 3.30    17.5      TAROT Calern
4.00 4.69    19.0      TAROT La Silla

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB160220B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19031
SUBJECT: Swift Trigger 674752 is likely a noise fluctuation in the direction of IGR17488-3253
DATE:    16/02/20 14:03:26 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Y. Lien (GSFC/UMBC), D. Malesani (DARK/NBI) and
K. L. Page (U Leicester) report on behalf of the Swift Team:

At 13:34:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a possible source near IGR17488-3253 (trigger=674752). 
Swift will not slew to the source as the ongoing observations of
GRB 160220B have a higher priority. 
The BAT on-board calculated location is 
RA, Dec 267.196, -32.939 which is 
   RA(J2000) = 17h 48m 47s
   Dec(J2000) = -32d 56' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is typical for image triggers, there is nothing
significant in the real-time TDRSS light curve. 

We note that this is a low significance trigger (5.9 sigma), part of
the sub-threshold program within BAT. Given that we lack XRT data, we
cannot at present confirm that the source is real. We will have to
wait until the full BAT dataset is transferred to ground to establish
the reality of this trigger. 


GRB_name: GRB160220A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19032
SUBJECT: GRB160220A: Swift/UVOT observations
DATE:    16/02/20 17:34:42 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>

M. De Pasquale (MSSL-UCL) and A. Lien (GSFC/UMBC) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160220A
4.11 ks after the BAT trigger (Lien et al., GCN Circ. 19023).
No optical afterglow consistent with the XRT position (Evans et al.
GCN Circ. 19025) is detected in the UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
summed UVOT exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white             4110         5493          344         >20.6
v                 4268        34517          903         >19.4
b                 5088         5288          197         >19.7
u                 4882        17290          424         >19.5

w1                4678        17052         1175         >20.3
m2                4472        11445         1271         >20.3
w2                5499        32840         1177         >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.13 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160220B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19033
SUBJECT: GRB160220B: Enhanced Swift-XRT position 
DATE:    16/02/20 19:20:32 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team:

Using 4686 s of XRT Photon Counting mode data and 8 UVOT images, we find
an astrometrically corrected X-ray position (using the XRT-UVOT alignment
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
259.86518, -18.12401 which is equivalent to:

RA (J2000):  17 19 27.64
Dec (J2000): -18 07 26.5

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received.  The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160219A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19035
SUBJECT: IPN Triangulation of GRB 160219A (short/hard)
DATE:    16/02/20 20:07:41 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, report:

A short-duration GRB 160219A has been detected by Konus-Wind, Fremi 
(GBM; trigger 477557782), Swift (BAT), and INTEGRAL (SPI-ACS), so far, 
at about 24978 s UT (06:56:18). The burst was outside the coded field of 
view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
--------------------------------
  RA(2000), deg    Dec(2000), deg
--------------------------------
Center:
    1.3524          -21.9573
Corners:
    352.3480        -23.1597
    350.3712        -23.9066
    9.4050          -15.0431
    7.6407          -16.0195
---------------------------------
The error box area is 18.39 sq. deg, and its maximum
dimension is 20.0 deg (the minimum one is 58 arcmin).
The Sun distance was about 20 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160219_T24973/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.


GRB_name: GRB160220B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19036
SUBJECT: GRB 160220B: Swift-XRT refined Analysis
DATE:    16/02/20 20:21:46 GMT
FROM:    Sarah Gibson at U.of Leicester  <slg44@leicester.ac.uk>

J. R. Cummings (NASA/UMBC) reports on behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 160220B (Cummings et al.
GCN Circ. 19029), from 3.3 ks to 16.9 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. Using 4686 s of PC mode
data and 8 UVOT images, we find an enhanced XRT position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 259.86518, -18.12401 which is equivalent to:

RA (J2000): 17h 19m 27.64s
Dec(J2000): -18d 07' 26.5"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.37 (+0.18, -0.17).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.17 (+0.25, -0.23). The
best-fitting absorption column is  4.3 (+1.2, -1.1) x 10^21 cm^-2, in
excess of the Galactic value of 2.6 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.6 x 10^-11 (6.3 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.3 (+1.2, -1.1) x 10^21 cm^-2
Galactic foreground: 2.6 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:      2.17 (+0.25, -0.23)

If the light curve continues to decay with a power-law decay index of
1.37, the count rate at T+24 hours will be 2.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.7 x
10^-14 (1.7 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00674734.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160220B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19037
SUBJECT: GRB160220B: Swift/UVOT observations
DATE:    16/02/20 21:42:50 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>

M. De Pasquale (MSSL-UCL) and J. Cummings (GSFC/UMBC) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160220B
3.33 ks after the BAT trigger (Cummings et al., GCN Circ. 19029).
No optical afterglow consistent with the XRT position (Evans et al.
GCN Circ. 19033) is detected in the UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
summed UVOT exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white             3735         5370          393         >21.0
v                 4145        10454         1082         >20.1
b                 3530         5165          393         >20.4
u                 4882        16950          451         >20.1

w1                4555        16884         1504         >20.9
m2                4350        11207          933         >20.7
w2                5499        32840         1170         >20.9

We note the presence of an uncatalogued source of magnitude 20.2 +/- 0.20
in white filter, at coordinates RA = 17h 19m 28.07, Dec = -18d 07m 25.5s
(J2000), which is 5" from the enhanced XRT position.

The magnitudes above are not corrected for the substantial Galactic 
extinction
due to the reddening of E(B-V) = 0.32 in the direction of the burst
(Schlegel et al. 1998).

-- 

Dr. Massimiliano De Pasquale
Research associate - Swift UVOT scientist
Mullard Space Science Laboratory, University College London


GRB_name: GRB160220A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19038
SUBJECT: GRB 160220A: Swift-BAT refined analysis
DATE:    16/02/20 21:43:14 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160220A (trigger #674670)
(Lien, et al., GCN Circ. 19023).  The BAT ground-calculated position is
RA, Dec = 236.942, -18.539 deg which is
    RA(J2000)  =  15h 47m 46.2s
    Dec(J2000) = -18d 32' 20.6"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask-weighted light curve shows a single peak of about 20 seconds total
duration starting at ~0 sec.  The spacecraft slewed away
from the burst location at ~T+220 sec due to a pre-planned maneuver.
T90 (15-350 keV) is 8.3 +- 1.2 sec (estimated error including systematics).

The time-averaged spectrum from T-0.02 to T+8.99 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.24.  The fluence in the 15-150 keV band is 5.2 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.33 sec in the 15-150 keV band
is 1.0 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/674670/BA/


GRB_name: GRB160220A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19039
SUBJECT: GRB 160220A: Swift-XRT refined Analysis
DATE:    16/02/20 22:09:50 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Maselli  (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U.
Leicester), P. D'Avanzo (INAF-OAB) and A.Y. Lien report on behalf of
the Swift-XRT team:

We have analysed 7.7 ks of XRT data for GRB 160220A (Lien et al. GCN
Circ. 19023), from 4.1 ks to 63.2 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 19025).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.94 (+0.20, -0.18).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.67 (+0.37, -0.18). The
best-fitting absorption column is  consistent with the Galactic value
of 1.1 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 4.0 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.1 (+/-1.1) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.67 (+0.37, -0.18)

If the light curve continues to decay with a power-law decay index of
0.94, the count rate at T+24 hours will be 3.9 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x
10^-13 (1.8 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00674670.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160220A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19040
SUBJECT: GRB 160220A: nIR observations at AAT
DATE:    16/02/20 22:50:57 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

R. Starling, N. Tanvir, K. Wiersema (U. Leicester) and J. Bailey (UNSW) report on behalf of a larger collaboration:

We observed the field of GRB 160220A (Swift trigger 674670, Lien et al. GCN Circ. 19023; Fermi trigger 477624330/16022005, Hui & Burns GCN Circ. 19026) 
with the 4m Anglo Australian Telescope, AAT, at Siding Spring, Australia on 2016 February 20th, 14 hours after burst.

We obtained near-IR photometry with the Infrared Imager and Spectrograph, IRIS2, in the Ks band beginning at 15:35 UT and in the J band beginning 16:09 UT, 
and totalling 27 minutes exposure in each filter. No source was detected within the Swift XRT error circle (Evans et al. GCN Circ. 19025).
We find the following approximate limiting magnitudes (at 5-sigma in the Vega system):
J > 21 
Ks > 18

We acknowledge excellent support from the Australian Astronomical Observatory staff. 


GRB_name: GRB160219A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19041
SUBJECT: GRB 160219A: Fermi GBM detection
DATE:    16/02/21 10:45:48 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung@mpe.mpg.de>

H.-F. Yu (MPE) and O. J. Roberts (UCD), 
report on behalf of the Fermi GBM Team:

"At 06:56:18.14 UT on the 19th of February 2015, the Fermi 
Gamma-Ray Burst Monitor (GBM) triggered and located GRB 160219A 
(trigger 477557782 / 160219289). The on-ground calculated location, 
using the Fermi GBM trigger data, is RA = 350.6, Dec = -29.7 deg.
(J2000 degrees, equivalent to 23h 22m 24s, -29d 42'), with a 
statistical uncertainty of 6.34 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic error which we 
have characterized as a core-plus-tail model, with 90% of GRBs having 
a 3.7 deg error and a small tail suffering a larger than 10 deg 
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). 

The angle from the Fermi LAT boresight for the IPN position 
is 51 degrees (Svinkin et al. 2016, GCN 19035).

The GBM light curve consists of two short pulses with a duration
(T90) of about 3.5 s (50-300 keV). The time-averaged spectrum from
T0-0.064 s to T0+3.456 s is best fit by a power law function with
an exponential high-energy cutoff. The power law index is
-0.97 +/- 0.15 and the cutoff energy, parameterized as Epeak, is
689 +/- 308 keV.

The event fluence (10-1000 keV) in this time interval is
(1.25 +/- 0.12)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.00 s in the 10-1000 keV band is
19.2 +/- 1.1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160220B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19042
SUBJECT: GRB 160220B: GROND Observations
DATE:    16/02/21 11:49:59 GMT
FROM:    Philip Wiseman at MPE/Swift  <wiseman@mpe.mpg.de>

P. Wiseman, J. Greiner (both MPE Garching) report on behalf of the GROND
team:

We observed the field of GRB 160220B (Swift trigger 674734; Cummings et
al., GCN #19029) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at  07:12 UT on 2016-02-21, ~20 hrs after the GRB
trigger. They were performed at an average seeing of 1.5" and at an
average airmass of 1.8.

We detect a single point source at the southern edge of the 1.5" enhanced
Swift-XRT error circle reported by Evans et al. (GCN #19033), at the
position RA, Dec (J2000) = 259.86531, -18.12433, which is equivalent to:

RA  =17h 19m 27.67s
Dec =-18d 07m 27.6s,

with an uncertainty of 0.3" in each coordinate.

Based on 72.00 min of total exposures at a mid-time of 07:54 UT, we
estimate a preliminary magnitude (AB system) of:

r' = 20.0 +/- 0.1

No statement about the variability of this source can be made at this time.

The given magnitude is calibrated against GROND zeropoints and is not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.25 mag in the direction of the burst (Schlafly &
Finkbeiner 2011).


GRB_name: GRB160220B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19043
SUBJECT: GRB 160220B: Swift-BAT refined analysis
DATE:    16/02/21 14:37:58 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160220B (trigger #674734)
(Cummings, et al., GCN Circ. 19029).  The BAT ground-calculated position is
RA, Dec = 259.851, -18.123 deg which is
    RA(J2000)  =  17h 19m 24.2s
    Dec(J2000) = -18d 07' 21.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 38%.

The mask-weighted light curve shows a double-peaked structure from T-10 to
T+40 seconds.  The spacecraft slewed away from the burst location at ~T+145
sec due to a pre-planned maneuver.  T90 (15-350 keV) is 31.4 +- 2.6 sec 
(estimated error including systematics).

The time-averaged spectrum from T-7.58 to T+37.54 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.75 +- 0.20,
and Epeak of 168.7 +- 56.3 keV (chi squared 39.67 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 7.0 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+6.46 sec in the 15-150 keV band is
6.6 +- 0.4 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.20 +- 0.05 (chi squared 56.26 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/674734/BA/


GRB_name: GRB160220B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19045
SUBJECT: Konus-Wind observation of GRB 160220B
DATE:    16/02/21 21:03:08 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team, report:

The long-duration GRB 160220B (Swift-BAT trigger #674734:
Cummings et al., GCN 19029; Lien et al., GCN 19043)
triggered Konus-Wind at T0=40259.435 s UT (11:10:59.435).

The burst light curve shows a single pulse
started at ~T0-12.8 s with a total duration of ~33.3 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160220_T40259/

As observed by Konus-Wind, the burst
had a fluence of 1.49(-0.11,+0.11)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.896 s,
of 4.32(-1.91,+1.92)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.84 (-0.22,+0.25)
and Ep = 197 (-20,+26) keV (chi2 = 47/62 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.4
(chi2 = 47/61 dof)

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.65 (-0.21,+0.24)
and Ep = 208 (-19,+23) keV (chi2 = 57/61 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.5
(chi2 = 57/60 dof)

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB160221A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19046
SUBJECT: GRB 160221A: A long GRB detected by INTEGRAL
DATE:    16/02/22 00:45:34 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro@iasf-milano.inaf.it>

S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, 
T.Favre (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the 
IBAS Localization Team report:

a gamma ray burst lasting about 10 s has been detected by IBAS in the 
IBIS/ISGRI data at 23:49:42 UT of February 21, 2016.

The refined coordinates (J2000) are:

R.A.=   232.0818 deg
DEC.=   -28.4337 deg

with an uncertainty of 2.5 arcmin (90% c.l.).

The burst had a peak flux of 1 counts/cm2/s (20-200 keV, 1-s integration 
time) and a fluence in the same energy range of about 5e-7 erg/cmq.

A plot of the light curve will be posted at 
http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB160221A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19047
SUBJECT: GRB 160221A: Swift ToO observations
DATE:    16/02/22 05:43:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the INTEGRAL GRB 160221A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020600

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the INTEGRAL event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160221A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19049
SUBJECT: GRB 160221A: MASTER-SAAO early observations 
DATE:    16/02/22 10:13:47 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

D.Buckley, S. Potter, M.Kotze, A.Kniazev
South African Astronomical Observatory

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, 
P.Balanutsa,  A.Kuznetsov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk, S. Yazev
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB160221A (Mereghetti et. al GCN 
19046) 61 sec after notice time and 74 sec after trigger time at 
2016-02-21 23:51:04 UT. On our second (10s exposure)  set we haven't found 
optical transient  within INTEGRAL error-box (ra=15 28 19 dec=-28 26 40 
r=0.053100).
The 5-sigma upper limit has been about 16.5 mag on single (10 s images) 
and 19.0 on coadd image with total exposure 150 s.

The message may be cited.


GRB_name: GRB160221A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19050
SUBJECT: GRB 160221A: Swift-XRT observations
DATE:    16/02/22 12:28:07 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Melandri (INAF-OAB), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M.
McCauley (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 160221A (Mereghetti et al. GCN Circ. 19046), collecting 1.3
ks of Photon Counting (PC) mode data between T0+21.3 ks and T0+25.8 ks.


One uncatalogued X-ray source has been detected inside or close to the
INTEGRAL error region, it is below the RASS limit and shows no
definitive signs of fading. Therefore, at the present time we cannot
confirm this as the afterglow. Details of this source are given below:

Source 1:
  RA (J2000):  232.0897  =  15:28:21.54
  Dec (J2000): -28.4552  =  -28:27:18.7
  Error: 4.5 arcsec (radius, 90% conf.)
  Count-rate: 0.0151 +/- 0.0040 ct s^-1
  Flux: (5.6 +/- 1.5)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Another uncatalogued was also detected, however this was too far from
the GRB position to be the afterglow.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020600.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160220B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19051
SUBJECT: Further Swift/UVOT observations of GRB 160220B
DATE:    16/02/22 13:52:57 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale@ucl.ac.uk>

M. De Pasquale, A.A. Breeveld (MSSL-UCL) and J. Cummings
(GSFC/UMBC) report on behalf of the Swift/UVOT team:

Following the detection of a source at the southern edge of the 1.5''
Swift-XRT error circle (Evans et al. GCN circ. 19033) by GROND
(Wiseman and Greiner, GCN Circ. 19042) we have re-analysed
our UVOT observations We caution that the anlysis is complicated
by a crowded field and large noise.

About at the sourthern edge of the XRT error circle we detect a source

RA = 17h 19m 27.64s (259.86517)
Dec = -18d 07m 30 s (-18.12500)

with an error of ~1''. The position of this source is
copatible with that of the oject detected by GROND.

Magnitudes of this source are given in the table below.

Filter         T_start(s)  T_stop(s)  Exp(s)     Mag
v              4145        10454       1082   18.7 +/- 0.2
b              3530         5165        393   19.4 +/- 0.2

The same source is detected  in successive exposures:

v              39730       62085       1072   18.7 +/- 0.2
b              44464       45371        885   19.4 +/- 0.2


As the source does not seem to have changed in brightness, we do
not think it is the optical afterglow of GRB160220B.

Magnitudes above are given in the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).

[GCN OPS NOTE(22feb16): Per Circ 19053, the Subject-line
has been corrected from "20A" to "20B".]


GRB_name: GRB160220B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19052
SUBJECT: GRB 160220B: Further GROND Observations
DATE:    16/02/22 14:04:03 GMT
FROM:    Philip Wiseman at MPE/Swift  <wiseman@mpe.mpg.de>

P. Wiseman, J. Bolmer and J. Greiner (all MPE Garching) report on behalf 
of the GROND team:

We once again observed the field of GRB 160220B (Swift trigger 674734; 
Cummings et al., GCN #19029) simultaneously in g'r'i'z'JHK with GROND 
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope 
at ESO La Silla Observatory (Chile).

Based on 36.00 min of total exposures in r', at a mid-time of 08:55 UT 
on 2016-02-22, ~1.9 days after the trigger, we do not detect any fading 
in the source reported by Wiseman et al. (GCN #19042), placing a limit 
on any magnitude change to < 0.1 mag in 24 hrs, in agreement with UVOT 
observations ( De Pasquale et al., GCN #19051).

We therefore agree that this source is likely not the afterglow of GRB 
160220B.


GRB_name: GRB160221A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19054
SUBJECT: GRB 160221A: GROND upper limits
DATE:    16/02/22 15:52:10 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

J. Bolmer, T. Kruehler, J. Greiner (all MPE Garching) report on behalf
of the GROND team:

We observed the field of the INTEGRAL GRB 160221A (Mereghetti et al.,
GCN #19046) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 05:12 UT on 2016-02-22, 5.4 hrs after the GRB
trigger. They were performed at an average seeing of 1.0" and at an
average airmass of 1.4.

No source within the Swift-XRT error circle (Melandri et al.,
GCN #19050) is detected. Based on 48.0 min of exposure in g'r'i'z'
and 43.3 min in JHK, at a mid-time of 06:43 UT, we derive the
following preliminary upper limits:

g' > 23.6 mag
r' > 24.3 mag
i' > 23.4 mag
z' > 23.4 mag
J  > 21.8 mag
H  > 21.1 mag
K  > 20.0 mag

Given limits are in the AB system and calibrated against GROND
zeropoints as well as 2MASS field stars. No correction for the expected
Galactic foreground extinction corresponding to a reddening of
E_(B-V)=0.26 mag in the direction of the burst (Schlafly &
Finkbeiner 2011) has been applied.


GRB_name: GRB160221A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19056
SUBJECT: GRB 160221A: Fermi GBM observation
DATE:    16/02/22 17:38:49 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>

C. M. Hui (NASA/MSFC) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 23:49:45.22 UT on 21 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160221A (trigger 477791389 / 160221993),
which was also detected by INTEGRAL (Mereghetti et al., GCN 19046).
The GBM on-ground location is consistent with the INTEGRAL position.

The angle from the Fermi LAT boresight at the GBM trigger time is 58 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 15 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+5.6 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.15 +/- 0.16 and
the cutoff energy, parameterized as Epeak, is 67 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(1.55 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.2 s in the 10-1000 keV band
is 4.0 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160223A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19057
SUBJECT: GRB 160223A: Swift detection of a burst
DATE:    16/02/23 02:11:02 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. B. Markwardt (NASA/GSFC), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC) and D. M. Palmer (LANL) report on behalf of
the Swift Team:

At 01:44:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160223A (trigger=675361).  Swift could not slew
immediately to the burst due to a Moon observing constraint. 
The BAT on-board calculated location is 
RA, Dec 147.584, +9.373 which is 
   RA(J2000) = 09h 50m 20s
   Dec(J2000) = +09d 22' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure near T+0 s about 30 seconds long, followed by an
additional brighter structure peaking at around T+100 for
a total duration of ~120 seconds.  The peak count rate
was ~2200 counts/sec (15-350 keV), at ~110 sec after the trigger. 

Due to the proximity to the Moon this GRB will not be observable by 
XRT or UVOT until 22:27UT on Feb 23rd, 2016. 

Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160223A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19058
SUBJECT: GRB 160223A: GROND optical/NIR afterglow
DATE:    16/02/23 07:18:53 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

J. Bolmer (MPE Garching), D. A. Kann (TLS Tautenburg), T. Kruehler,
and J. Greiner (both MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 160223A (Swift trigger 675361; Markwardt et
al., GCN #19057) simultaneously in g'r'i'z'JHK with GROND (Greiner
et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the
ESO La Silla Observatory (Chile).

Observations started at 03:30:41 UT on 2016-02-23, 106 min after the GRB
trigger. They were performed at an average seeing of 1".2 and at an
average airmass of 1.3.

We find a bright, uncatalogued point source within the Swift-BAT error
circle at

RA (J2000) = 09:50:23.34
Dec. (J2000) = +09:22:09.0

with an uncertainty of 0".5 in each coordinate.

Based on the first 4.4 min of total exposure in g'r'i'z' and 4.0 min
in JHK at a mid-time of 03:34:13 UT, we derive the following preliminary
magnitudes (all in AB system):

g = 17.8 +- 0.1 mag
r = 16.9 +- 0.1 mag
i = 16.5 +- 0.1 mag
z = 16.2 +- 0.1 mag
J = 16.1 +- 0.1 mag
H = 15.9 +- 0.1 mag
K = 15.8 +- 0.1 mag

The object fades by 0.4 mag until 04:55 UT on 2016-02-23, so we
propose this source to be the optical/NIR afterglow of GRB 160223A.

Given magnitudes are calibrated against SDSS as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V) = 0.03 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).

[GCN OPS NOTE(23feb16):  Per author's request, DAK was added to the author list.]


GRB_name: GRB160223B
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19059
SUBJECT: GRB 160223B: A long GRB detected by INTEGRAL
DATE:    16/02/23 10:54:09 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

D.Gotz (CEA, Saclay), S.Mereghetti (IASF-Milano), C.Ferrigno, E.Bozzo, S. Fotopoulou(ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report:
a gamma ray burst lasting about 30 s has been detected by IBAS in the IBIS/ISGRI data at 09:58:58 UT of February 23, 2016.

The refined coordinates (J2000) are:

R.A.=   94.9937 deg
DEC.=   +33.4075 deg

with an uncertainty of 2.2 arcmin (90% c.l.).

The burst had a peak flux of 1.2 counts/cm2/s (20-200 keV, 1-s integration 
time) and a fluence in the same energy range of about 1.6e-6 erg/cmsq.

A plot of the light curve will be posted at 
http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB160223B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19060
SUBJECT: GRB 160223B: Swift ToO observations
DATE:    16/02/23 12:55:22 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the INTEGRAL GRB 160223B. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020601

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the INTEGRAL event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160223B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19061
SUBJECT: GRB 160223B: Fermi GBM observation
DATE:    16/02/23 15:27:58 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin, H.-F. Yu, and K. Toelge (all MPE) 
report on behalf of the Fermi GBM Team:

"At 09:59:01.51 UT on 23 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160223B (trigger 477914345 / 160223416),
which was also detected by INTEGRAL (GÃ¶tz et al. 2016, GCN 19059)
The GBM on-ground location is consistent with the INTEGRAL position.

The angle from the Fermi LAT boresight at the GBM trigger time is 49 degrees.

The GBM light curve shows a structured pulse
with a duration (T90) of about 17 s (50-300 keV).
The time-averaged spectrum from T0-2.560 s to T0+16.896 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.90 (+0.08/-0.07)  and
the cutoff energy, parameterized as Epeak, is 560 (+110 /-80) keV

The event fluence (10-1000 keV) in this time interval is
(5.9 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+0.256 s in the 10-1000 keV band
is 3.1 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160223B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19062
SUBJECT: GRB 160223B: LCOGT-FTN optical observations
DATE:    16/02/23 20:02:48 GMT
FROM:    Simone Dichiara at Ferrara U/Italy  <dichiara@fe.infn.it>

S. Dichiara, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU),
A. Gomboc (U. Nova Gorica), C.G. Mundell (U. Bath), on behalf
of a larger collaboration report:

The 2-m LCOGT Faulkes Telescope North began observing
INTEGRAL and Fermi GRB 160223B (Gotz et al. GCN 19059,
von Kienlin et al., GCN 19061) on Feb 23 at 10:06:58 UT
(7.8 minutes after the burst trigger) with r filter.
We do not detect any optical afterglow candidate within the
INTEGRAL error circle (Gotz et al. GCN 19059) down to the
following magnitudes:

Mid Time      Exposure       Filter       Magnitude
(min)           (s)
-------------------------------------------------------
12.27          5x120            r'          > 20.5
-------------------------------------------------------

Values have been calibrated against nearby USNOB-1 stars
(R2)


GRB_name: GRB160223B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19063
SUBJECT: GRB 160223B: Swift-XRT observations
DATE:    16/02/23 21:18:36 GMT
FROM:    Andy Beardmore at U Leicester  <ab271@leicester.ac.uk>

T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), S.L.
Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 160223B (Gotz et al. GCN Circ. 19059), collecting 2.3 ks of
Photon Counting (PC) mode data between T0+10.6 ks and T0+16.4 ks. 

No X-ray sources have been detected inside or close to the INTEGRAL
error region. The 3-sigma upper limit in the field ranges from ~0.004
to ~0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of
1.8e-13 to 1.9e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020601.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160223A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19064
SUBJECT: GRB 160223A: Fermi GBM observation
DATE:    16/02/23 21:35:50 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH), K Toelge (MPE), C Meegan (UAH)  and C M Hui (MSFC)
report on behalf of the Fermi GBM Team:

"At 01:44:22.39 UT on 23 February 2016, the Fermi Gamma-Ray Burst
Monitor triggered
and located GRB 160223A (trigger 477884666 / 160223072) which was also
detected by the Swift/BAT
(Markwardt et al., GCN 19057). The GBM on-ground location is consistent
with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 75
degrees.

The GBM light curve shows two separate peaks
with a duration (T90) of about 117 s (50-300 keV).
The time-averaged spectrum from T0-6 s to T0+124 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.96 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 308 +/- 30 keV.

The event fluence (10-1000 keV) in this time interval is
(1.46 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.7 s in the 10-1000 keV band
is 5.4 +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 282 +/- 45 keV, alpha = -0.94 +/- 0.08 and beta = -2.20 +/-
0.23.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB160223B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19065
SUBJECT: GRB 160223B: Khureltogot optical observations
DATE:    16/02/24 01:31:17 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), S. Schmalz (ISON), A. Volnova (IKI),  N. Tungalag 
(Research Center of Astronomy and Geophysics MAS),   I. Molotov (KIAM),
 A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of INTEGRAL and Fermi GRB 160223B GRB 160223B (Gotz et 
al. GCN 19059; von Kienlin et al., GCN 19061) with ORI-40 telescope of 
Khureltogot observatory starting on Feb., 23 (UT) 12:34:31.  Within 2.2 
arcmin error circle of the GRB 160223B localization  (Gotz   et al., GCN 
19059) we marginally detect two possible sources not presented in USNO-B1.0 
catalog. Coordinates of the sources are

Source (1): (J2000) 6:20:05.53 +33:24:58.7
Source (2): (J2000) 6:20:03.89 +33:23:14.2

with uncertainties of 1 arcsec in both coordinates.
At this time we cannot confirm the sources are real  or variable due to low 
S/N and absence of a full dataset.

Preliminary photometry of the sources is following


Date UT start       t-T0   Filter Exp.   OT   Err   UL(3sigma) Source#
                     (mid, days)   (s)

2016-02-23 12:34:31  0.14969 none  7200   18.7 0.35  18.9  (1)
2016-02-23 12:34:31  0.14969 none  7200   18.7 0.30  18.9  (2)

Photometry is based on nearby USNO-B1.0  stars, R2 magnitudes:
USNO-B1_id        R2
1234-0146334    14.41
1234-0146221    14.55
1233-0156534    14.77
1234-0146470    13.48
1234-0146172    13.37


GRB_name: GRB160223A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19066
SUBJECT: GRB 160223A: Swift-BAT refined analysis
DATE:    16/02/24 07:39:55 GMT
FROM:    Tilan Ukwatta at LANL  <tilan.ukwatta@gmail.com>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+581 sec from the recent
telemetry downlink, we report further analysis of BAT GRB
160223A (trigger #675361) (Markwardt, et al., GCN Circ.
19057). The BAT ground-calculated position is
RA, Dec = 147.603, 9.369 deg which is
   RA(J2000)  =  09h 50m 24.8s
   Dec(J2000) = +09d 22' 09.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat,
90% containment). The partial coding was 53%.

BAT light curve shows two episodes. The first episode
starts ~T-10 sec, peaks at ~T+0 sec and ends around ~T+20 sec.
The second multi-peaked episode starts around T+70 sec and
ends around ~T+120 sec. T90 (15-350 keV) is
127 +- 8 sec (estimated error including systematics).

The time-averaged spectrum from T-6.00 to T+143.13 sec
is best fit by a simple power-law model.  The power law
index of the time-averaged spectrum is 1.34 +- 0.07.
The fluence in the 15-150 keV band is
5.0 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux
measured from T+109.95 sec in the 15-150 keV band is
3.1 +- 0.2 ph/cm2/sec.  All the quoted errors are at
the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/675361/BA/


GRB_name: GRB160223B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19069
SUBJECT: GRB 160223B: MASTER-Amur early observations
DATE:    16/02/24 08:47:56 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

N.Tyurina, V. Lipunov, E. Gorbovskoy,  V.Kornilov, 
P.Balanutsa, A.Kuznetsov, D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

MASTER-Amur  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160223B  32 sec after 
trigger time at 2016-02-23 09:59:30 UT. On 
our first  set  (10 sec,  unfiltered) we  not found optical transients 
within  INTEGRAL error-box (ra=06 19 54 dec=+33 24 21 r=2'.2 ) brighter 
then  15.8.

The message may be cited.


GRB_name: GRB160219A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19070
SUBJECT: Konus-Wind observation of GRB 160219A
DATE:    16/02/24 13:42:14 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko,
and T. Cline, on behalf of the Konus-Wind team, report:

The short-duration, hard-spectrum GRB 160219A
(IPN triangulation: Svinkin et al., GCN 19035;
Fermi-GBM detection: Yu & Roberts, GCN 19041)
triggered Konus-Wind at T0=24973.245 s UT (06:56:13.245).

The burst light curve starts with a short (~0.09 s) pulse,
followed by a weaker pulse at ~T0+3.1 s (with a duration of~0.96 s).

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB160219_T24973/

As observed by Konus-Wind, the burst had a fluence of
1.57(-0.21,+0.25)x10^-6 erg/cm2 and a 16-ms peak flux,
measured from ~T0-0.028 s, of 1.22(-0.27,+0.27)x10^-5 erg/cm2/s
(both in the 20 - 1200 keV energy range).

Since the bulk of the burst emission was detected before
the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modelling the K-W 3-channel spectrum of the first pulse
(measured from T0-0.066 s to T0+0.022 s)
by the cutoff power law yields the following model parameters:
the photon index alpha = -0.29(-0.37,+0.55),
and the peak energy Ep = 753(-187,+395) keV.

Modelling the K-W 3-channel spectrum of the second pulse
(measured from T0+3.072 s to T0+4.032 s)
by the cutoff power law yields the following model parameters:
the photon index alpha = -0.98(-0.22,+0.73),
and a lower limit on the Ep: Ep > 760 keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB160223A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19072
SUBJECT: GRB 160223A: AbAO optical observations
DATE:    16/02/24 20:22:47 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), R. Inasaridze (AbAO), V. Ayvazian (AbAO), A. Volnova 
(IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger
GRB follow-up collaboration:

We observed the field of Swift and Fermi GRB 160223A (Markwardt et
al., GCN 19057; Veres  et al., GCN 19064) with AS-32 (0.7m) telescope of 
Abastumani Observatory starting on Feb. 23 (UT) 23:51:22. We obtained 
several unfiltered images of the field. We do not detect afterglow 
candidate (Bolmer et al., GCN 19058) down to 20.4m. A preliminary 
photometry of the field is following


Date         UT start      t-T0       Filter     Exp.    UL (3 sigma)
                              (mid, days)           (s)

2016-02-23 23:51:22    0.96907  none    21*120  20.4

photometry is based on nearby  stars of SDSS DR9 catalog, Lupton 
transformation into R.


GRB_name: GRB160221A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19073
SUBJECT: GRB 160221A: Swift-XRT afterglow detection
DATE:    16/02/25 07:48:54 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

A. Melandri (INAF-OAB), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M.
McCauley (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
INTEGRAL-detected burst GRB 160221A (Mereghetti et al. GCN Circ.
19046). The observations now extend from T0+21.3 ks to T0+274.5 ks. The
source previously reported by Melandri et al. (GCN Circ. 19050),
"Source 1", is fading with 3-sigma significance, and is therefore
likely the GRB afterglow.  The position of this source is RA,
Dec=232.0895, -28.4551 which is equivalent to:

RA (J2000): 15:28:21.48
Dec(J2000): -28:27:18.4

with an uncertainty of 4.1 arcsec (radius, 90% confidence).  This
position is 80 arcsec from the INTEGRAL position.  The source is fading
with alpha >0.5.

The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00020600/index_1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020600.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160223A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19074
SUBJECT: GRB 160223A: Swift-XRT afterglow detection
DATE:    16/02/25 13:19:17 GMT
FROM:    Andy Beardmore at U Leicester  <ab271@leicester.ac.uk>

L.M. McCauley (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester),
K.L. Page (U. Leicester), C. Pagani (U. Leicester), V. D'Elia (ASDC),
A. D'Ai (INAF-IASFPA), A. Maselli  (INAF-IASFPA), B. Sbarufatti
(INAF-OAB/PSU) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 160223A (Markwardt et al. GCN Circ.
19066), collecting 8.3 ks of Photon Counting (PC) mode data between
T0+109.9 ks and T0+197.1 ks. 

An uncatalogued X-ray source has been detected inside the Swift/BAT
error region, at a location consistent with the GROND afterglow
candidate (GCN Circ. 19058).  The position of this source is RA,
Dec=147.5977, +9.3696 which is equivalent to:

RA (J2000): 09:50:23.46
Dec(J2000): +09:22:10.4

with an uncertainty of 6.6 arcsec (radius, 90% confidence).  This
location is 2.3 arcsec from the reported GROND position.  The observed
count rate is (1.69 +/- 0.75)e-3 ct s^-1, which corresponds to an
observed 0.3-10 keV flux of (3.7 +/- 1.7)e-14 erg cm^-2 s^-1.  We
cannot determine at the present time whether the source is fading.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00675361.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160225A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19075
SUBJECT: GRB 160225A: Swift detection of a burst
DATE:    16/02/25 14:42:58 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. H. Siegel (PSU), A. P. Beardmore (U Leicester),
P.A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), L. M. McCauley (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. G. R. Roegiers (PSU), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (LANL) report on behalf
of the Swift Team:

At 14:20:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160225A (trigger=675998).  Swift's slew was briefly
delayed due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 164.242, +53.655 which is 
  RA(J2000) = 10h 56m 58s
  Dec(J2000) = +53d 39' 19"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed multiple spikes
over a 50 second interval.  The peak count rate
was ~1500 counts/sec (15-350 keV) at ~3 sec after the trigger. 

The XRT began observing the field at 14:34:50.6 UT, 834.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 164.22846, 53.66991 which is equivalent
to:
   RA(J2000)  = 10h 56m 54.83s
   Dec(J2000) = +53d 40' 11.7"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 60 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (9.69 x
10^19 cm^-2, Willingale et al. 2013), with an excess column of 3.8
(+4.26/-3.38) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 839 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160225A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19076
SUBJECT: GRB 160225A: MASTER-Amur early observations 
DATE:    16/02/25 14:47:57 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, N.Tyurina, V. Lipunov, V.Kornilov, 
P.Balanutsa, A.Kuznetsov,  D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160225A 20 sec after 
notice time and 204 sec after Swift BAT trigger time at 2016-02-25 
14:24:20 UT (Siegel et al, 19075). On 
our first (40s exposure)  set we haven't found optical transient  within 
SWIFT error-box (ra=10 56 58 dec=+53 39 17 r=0.050000).
The 5-sigma upper limit has been about 17.5 mag

The message may be cited.


GRB_name: GRB160225A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19077
SUBJECT: GRB 160225A: Enhanced Swift-XRT position
DATE:    16/02/25 17:22:20 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2168 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160225A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 164.22971, +53.66998 which is equivalent
to:

RA (J2000): 10h 56m 55.13s
Dec (J2000): +53d 40' 11.9"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB160225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19078
SUBJECT: GRB 160225A: TSHAO optical upper limit
DATE:    16/02/25 17:37:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Kusakin (Fesenkov Astrophysical Institute), I. 
Reva (Fesenkov Astrophysical Institute), A. Volnova (IKI),  A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the Swift GRB 160225A (Siegel  et al., GCN 19075) with 
Zeiss-1000 (West) 1-m telescope of Tien Shan Astronomical Observatory. 
We obtained several images in R filter starting on  Feb. 25 (UT) 
14:46:05. In the first images we do not detect any optical source within 
enhanced Swift-XRT position (Goad et al., GCN 19077). Preliminary 
photometry of one of  single 90 s image is following


Date        UT start   t-T0    Filter  Exp.   UL (3sigma)
                       (mid, days)     (s)


2016-02-25 14:47:35   0.01903  R      1*90    18.90


GRB_name: GRB160223A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19079
SUBJECT: GRB 160223A: RATIR Optical and NIR Observations
DATE:    16/02/25 17:46:00 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM),
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We first observed the field of GRB 160223A (Markwardt, et al., GCN 19057)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2016/02 23.15 to 2016/02 23.49 UTC
(3.65 to 11.79 hours after the BAT trigger), obtaining a total of 5.04
hours exposure in the r and i bands and 2.26 hours exposure in the Z, Y, J,
and H bands.  We observed a second time from 2016/02 24.12 to 2016/02 24.49
UTC (26.78 to 35.78 hours after the BAT trigger), obtaining a total of 5.02
hours exposure in the r and i bands and 2.12 hours exposure in the Z, Y, J,
and H bands.

We detect the afterglow (Bolmer, et al., GCN 19058) cleanly in the first
epoch.  In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the
following magnitudes:

 r = 18.13 +/- 0.01
 i = 17.43 +/- 0.01
 Z = 17.37 +/- 0.01
 Y = 17.20 +/- 0.01
 J = 17.08 +/- 0.01
 H = 16.81 +/- 0.01

The source is clearly fading during the first epoch.  In the second epoch,
we do not detect the source.  We obtain the following (3-sigma) upper
limits:

 r > 22.38
 i > 22.05
 Z > 21.49
 Y > 21.44
 J > 21.35
 H > 21.26

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160225A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19080
SUBJECT: GRB 160225A: MITSuME Akeno Optical Observation
DATE:    16/02/25 17:53:11 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

T. Yoshii, Y.Saito, T.Fujiwara, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 160225A (M. H. Siegel et al., GCN 
Circular #19075) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm 
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2016-01-04 14:24:14 UT (198 sec after the burst) and 
we detected the optical counterpart in Rc and Ic band.
The measured magnitudes were listed as follows.

We obtained following limits for the magnitudes.

T0+[sec]    MID-UT      T-EXP[sec]         g'              Rc                      Ic
-------------------------------------------------------------------------------------------------------
378            14:27:14             270            > 19.4        18.2 +/- 0.1        17.1 +/- 0.2 
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB160225A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19081
SUBJECT: GRB 160225A: MITSuME Okayama Optical Observation
DATE:    16/02/25 23:50:50 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:

We observed the field of GRB 160225A (Siegel et al., GCNC 19075)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2016-02-25 14:26:51 UT (~5.9 min after
the burst). We detected the previously reported afterglow (Yoshii
et al., GCNC 19080) in Rc and Ic bands.

Photometric results and three sigma upper limit of the OT are
listed below. We used SDSS-DR7 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc  Rc_err  Ic  Ic_err
------------------------------------------------------------------
0.00777    14:32:08     540.0   >19.4   18.6 0.2    17.8 0.2
------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB160225A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19082
SUBJECT: GRB 160225A: WHT LIRIS observations
DATE:    16/02/26 00:01:37 GMT
FROM:    Klaas Wiersema at U Leicester  <kw113@leicester.ac.uk>

K. Wiersema, N. Tanvir (U. of Leicester),  A. Levan (U. of Warwick)
and G. Pugliese (API/UvA) report:

We observed the position of GRB 160225A (Siegel et al. GCN 19075) with 
the 4.2m William Herschel Telescope (WHT). Using the LIRIS instrument
we obtained 20x60 sec in Y band, 20x60 sec in J band and 60x20 sec in Ks band.
Observations started at 19:57 UT on 25 February 2016 (i.e. 5.62 hours after
burst).
A point source is clearly detected near the enhanced XRT position 
(Goad et al. GCN 19077), at position:
RA (J2000):  10 56 55.18
Dec (J2000): +53 40 13.7
with an uncertainty of 0.5 arc seconds. The source is seen in all three
filters, and has magnitudes J~20.6 mag and Ks~19.2 mag (Vega magnitudes, 
calibrated using 2MASS objects in the field).

We acknowledge excellent support from Raine Karjalainen (ING).


GRB_name: GRB160225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19083
SUBJECT: GRB 160225A: NOT optical observations
DATE:    16/02/26 02:10:23 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC/CAS), D. Malesani (DARK/NBI), N. Tanvir (U. of Leicester), 
A. Kvammen (NOT) report on behalf of a large collaboration:

We observed the field of GRB 160225A (Siegel et al. GCN 19075) using the 
2.56m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. 
Observations started at 23:31:27 UT on 2016-02-25 (i.e., 8.56 hr 
post-burst) and 9x200s exposures were obtained in the Sloan r- and 
i-band, respectively.

The optical afterglow is detected at the WHT position (Wiersema et al., 
GCN 19082) and presumably also the MITSuME position (Yoshii et al. GCN 
19080). We measured m(r)=23.25 +/- 0.15 at 8.86 hr post-burst and m(i) = 
22.55 +/- 0.07 at 9.48 hr post-burst, calibrated with nearby SDSS stars.


GRB_name: GRB160225A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19084
SUBJECT: GRB 160225A: Swift-XRT refined Analysis
DATE:    16/02/26 02:36:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester),
A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Maselli 
(INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU),
D.N. Burrows (PSU) and M.H. Siegel report on behalf of the Swift-XRT
team:

We have analysed 9.4 ks of XRT data for GRB 160225A (Siegel et al. GCN
Circ. 19075), from 841 s to 31.8 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Goad et al. (GCN Circ. 19077).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.91 (+/-0.06).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.11 (+/-0.14). The
best-fitting absorption column is  5.7 (+3.0, -2.7) x 10^20 cm^-2, in
excess of the Galactic value of 9.7 x 10^19 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.0 x 10^-11 (3.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.7 (+3.0, -2.7) x 10^20 cm^-2
Galactic foreground: 9.7 x 10^19 cm^-2
Excess significance: 2.9 sigma
Photon index:      2.11 (+/-0.14)

If the light curve continues to decay with a power-law decay index of
0.91, the count rate at T+24 hours will be 0.013 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.9 x
10^-13 (4.5 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00675998.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB160223B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19085
SUBJECT: GRB 160223B: CALET Gamma-Ray Burst Monitor detection
DATE:    16/02/26 03:05:55 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Ozawa (Wasoeda U), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
K. Senuma, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB160223B (Gotz et al., GCN Circ. 19059; von Kienlin et al., GCN Circ. 19061) 
triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 09:58:59.5 on 23 February 2016.  
The burst signal was detected by SGM instrument.  

The light curve of the SGM shows at least three peaks.  The emission starts at T0, 
peaks at T0+1 sec and ends at T0+25 sec.   The T90 duration measured by the SGM data 
is 11 +- 1 sec (40-1000 keV). 

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.


GRB_name: GRB160225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19086
SUBJECT: GRB 160225A: Xinglong TNT optical observation
DATE:    16/02/26 03:35:09 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin, X. F. Wang, J. Y. Wei, X. H. Han, Y. L. Qiu,
J. Wang, C. Wu, J. S. Deng report:

We  observed  GRB 160225A (Siegel et al. GCN 19075)  with
80cm TNT telescope, located at Xinglong obervatory, China,
at 14:24:26 UT,  about 3.5 min after the burst.
The optical afterglow (Wiersema et al., GCN 19082) near the 
enhanced XRT errorbox (Goad et al., GCN 19082) was  detected 
in our white and R-band  images.  

The brightness of the optical afterglow  is about 17.58 mag 
at the mid time  of 3.67 min afer the burst,  calibrated by 
the USNO B1.0 star (RA=10:56:59.4  DEC=+53:40:45  R2=15.26mag).
 
We thank  excellent support of the Xinglong 80cm TNT staff, 
particularly YunPeng Wang.

The message may be cited.


GRB_name: GRB160225A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19087
SUBJECT: GRB 160225A: Swift/UVOT Upper Limits
DATE:    16/02/26 05:10:10 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160225A
839 s after the BAT trigger (Siegel et al., GCN Circ. 19075).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 19077) or the previously reported
optical position (Wierema, et al., GCN Circ. 19082) 
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           839          989          147         >20.7
white              839         2657          342         >21.1
v                 1121         2708          194         >19.9
b                 1047         2632          194         >20.8
u                 1022         2608          156         >19.9
w1                 998         3036          311         >20.1
m2                1494         2912          236         >20.2
w2                1446         2683           78         >20.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB160225A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19088
SUBJECT: GRB 160225A: RATIR Optical and NIR Observations
DATE:    16/02/26 07:25:27 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM),
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160225A (Siegel, et al., GCN 19075) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/02 26.13 to 2016/02 26.28 UTC (12.72 to
16.34 hours after the BAT trigger), obtaining a total of 2.47 hours
exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H
bands.

We detect the WHT afterglow candidate (Wiersema, et al., GCN 19082), and
find it to have faded.  In comparison with the SDSS DR9 and 2MASS catalogs,
we obtain the following detections and upper limits (3-sigma):

  r > 24.09
  i = 23.03 +/- 0.16
  Z = 22.17 +/- 0.19
  Y > 22.35
  J = 22.06 +/- 0.33
  H > 21.74

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The r-band faintness suggests that
this may be a moderate to high-z source.  Fitting Milky Way, LMC, and SMC
Exctinction Laws in Addition to the IGM (see, Littlejohns, et al. 2014), we
find a photo-z of 5.54 (+0.35,-5.11; 90% conf.).  Hence, a high-z solution
is preferred, but a low-z origin is not ruled out.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160225A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19089
SUBJECT: GRB 160225A: MASTER-Amur  observations 
DATE:    16/02/26 09:27:38 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

N.Tyurina, E. Gorbovskoy, V. Lipunov, V.Kornilov, P.Balanutsa, 
A.Kuznetsov, D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Blagoveschensk was pointed to the  GRB160225A 20 sec after
notice time and 204 sec after Swift BAT trigger (Siegel et al, 19075) 
time at 2016-02-25 14:24:20 UT (Gabovich  et al, 19076).

We did not see any OT brighter 2-sigma. Our unfiltered camera sensitive up 
to 10  mk.


  Id   t_start-t_trigger    t_mean-t_trig   Exp.time   Limit
                   s                 s            s            unfiltered

767291  204                224          40         17.4
767293          256                281          50              17.6 
767295          318                348          60              17.0
769139          318                768         600              18.7 
769244          318               1187       1200          19.0

Our unfiltered magnitude calibrated to USNOB1 stars as m =0.2B + 0.8R .

The message may be cited.


GRB_name: GRB160225A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19091
SUBJECT: GRB 160225A: Swift-BAT refined analysis
DATE:    16/02/26 15:16:08 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), 
M. H. Siegel (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160225A (trigger #675998)
(Siegel, et al., GCN Circ. 19075).  The BAT ground-calculated position is
RA, Dec = 164.217, 53.659 deg which is 
   RA(J2000)  =  10h 56m 52.1s 
   Dec(J2000) = +53d 39' 33.6" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
 
The mask-weighted light curve shows a multiple peak structure starting 
at T0-30 sec and ending at T0+50 sec.  Although there is a hint of 
a emission after T0+100 sec, no data are available after T0+150 sec because 
the spacecraft slewed away to the GRB.  T90 (15-350 keV) is 157 +- 70 sec 
(estimated error including systematics).
 
The time-averaged spectrum from T-30.38 to T+135.29 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.23.  The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+37.13 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/675998/BA/


GRB_name: GRB160225A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19093
SUBJECT: GRB 160225A: Continued RATIR Optical and NIR Observations
DATE:    16/02/26 16:52:29 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
JosÃ© A. de Diego (UNAM), Leonid Georgiev (UNAM), JesÃºs GonzÃ¡lez (UNAM),
Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 160225A (Siegel, et al., GCN 19075) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2016/02 26.13 to 2016/02 26.51 UTC (12.72 to
21.97 hours after the BAT trigger), obtaining a total of 6.38 hours
exposure in the r and i bands and 2.68 hours exposure in the Z, Y, J, and H
bands.

With continued exposure (see, Butler, et al., GCN 19088), we now detect the
WHT afterglow candidate (Wiersema, et al., GCN 19082) in all bands.  In
comparison with the SDSS DR9 and 2MASS catalogs, we find:

 r = 23.84 +/- 0.18
 i = 23.13 +/- 0.11
 Z = 22.71 +/- 0.18
 Y = 22.40 +/- 0.22
 J = 22.44 +/- 0.26
 H = 22.04 +/- 0.26

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We have fitted our photometry with a power-law source and redshifted Milky
Way, LMC, or SMC extinction laws and IGM extinction (see, Littlejohns, et
al. 2014). The detection in r conclusively rules out solutions with z > 5.
However, there are a range of solutions up to z ~ 4.5.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB160225B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19095
SUBJECT: IPN Triangulation of GRB 160225B
DATE:    16/02/26 21:45:56 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, report:

The long-duration GRB 160225B has been detected by Fermi (GBM; trigger 
478121069), Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), so far, at 
about 69865 s UT (19:24:25). The burst was outside the coded field of 
view of the BAT.

We have triangulated it to a preliminary annulus centered
at RA(2000)=174.671 deg (11h 38m 41s)  Dec(2000)=+0.848 deg (+0d 50' 
52"), whose radius is 43.602 +/- 8.004 deg (3 sigma). The minimum 
distance between the center line of this annulus and the MASTER-NET 
optical transient (Buckley, et al., GCN Circ. 19092 and 19094) is 19.5 
arcmin, so the association of the OT and the GRB cannot be ruled out 
based on the triangulation only.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160225_T69916/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.


GRB_name: GRB160225B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19096
SUBJECT: GRB 160225B: Fermi GBM detection
DATE:    16/02/26 23:54:49 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>

C. M. Hui (NASA/MSFC), E. Burns (UAH), and C. Meegan (UAH)
reports on behalf of the Fermi GBM Team:

At 19:24:25.39 UT on 25 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160225B (trigger 478121069 / 160225809)
which was also triangulated by IPN (Svinkin et al., GCN 19095)

The on-ground calculated location, using the GBM trigger data, 
is RA = 150.19 , DEC = -34.71  (J2000 degrees, 
equivalent to 10h 00m, -34d 42.0'), with an uncertainty of 1.00 degrees
(radius, 1-sigma containment, statistical only; there is additionally 
a systematic error which we have characterized as a core-plus-tail model,
with 90% of GRBs having a 3.7 deg error and a small tail suffering 
a larger than 10 deg systematic error. 
[Connaughton et al. 2015, ApJS, 216, 32]). 

The angle from the Fermi LAT boresight is 100 degrees.

The GBM light curve shows two peaks
with a duration (T90) of about 64 s (50-300 keV).
The time-averaged spectrum from T0+43.009 s to T0+74.753 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.91 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 124.10 +/- 3.30 keV.

The event fluence (10-1000 keV) in this time interval is
 (1.434 +/- 0.023)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+54.27 s in the 10-1000 keV band is 12.89 +/- 0.37 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog.


GRB_name: GRB160225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19097
SUBJECT: GRB 160225A: LOAO optical upper limit
DATE:    16/02/27 12:16:10 GMT
FROM:    Soomin Jeong at IAA-CSIC  <sjeong@iaa.es>

S. Jeong (SKKU/IAA-CSIC), M. Im (SNU), Y. Urata (NCU), I. H. Park (SKKU) on behalf of larger collaboration:

We observed the field of GRB 160225A (Siegel, et al., GCN 19075) with the 1m telescope of Mt. Lemmon Optical Astronomy Observatory (LOAO) in Arizona. 
The series of images are taken in R filter starting on Feb. 26 02:45:36 UT (~12.4 hr post burst). We do not detect any optical afterglow candidate within the 
XRT enhanced error circle (Goad et al., GCN 19077) down to the following magnitudes calibrated with the nearby USNO-B1.0 stars. The non-detection is consistent with 
the previous UL report in similar epoch (Butler, et al., GCN 19088). 
Mid Time      Exposure       Filter       Magnitude
(hr)           (s)
-------------------------------------------------------
12.83         9x300            R          > 21.5
-------------------------------------------------------
USNO-B1.0_id   R1    R2       
1436-0208445 14.73 15.26  14.995
1436-0208447 13.55 13.74  13.645


GRB_name: GRB160227A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19098
SUBJECT: GRB 160227A: Swift detection of a burst with an optical counterpart
DATE:    16/02/27 19:46:27 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. H. Siegel (PSU), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),
L. M. McCauley (PSU), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (LANL) report on behalf
of the Swift Team:

At 19:32:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160227A (trigger=676423).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 194.788, +78.639 which is 
   RA(J2000) = 12h 59m 09s
   Dec(J2000) = +78d 38' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a early complex
structure followed by a stronger peak at around 100 s after the trigger,
for a total duration of at least 160 s.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~100 sec after the trigger. 

The XRT began observing the field at 19:34:39.9 UT, 151.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 194.7974, 78.6768 which is equivalent to:
   RA(J2000)  = +12h 59m 11.38s
   Dec(J2000) = +78d 40' 36.5"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 136 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 2.67e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 161 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 12:59:13.84 = 194.80767
  DEC(J2000) = +78:40:44.9  =  78.67913
with a 90%-confidence error radius of about 0.77 arc sec. This position is 11.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.32 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.05. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB160227A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19099
SUBJECT: GRB 160227A: MASTER OT Detection 
DATE:    16/02/27 19:49:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

E. Gorbovskoy, V. Lipunov,N.Tyurina, V.Kornilov, P.Balanutsa, 
A.Kuznetsov,  D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Ural was pointed to the  GRB160227A 30 after 
notice time and 115 sec after trigger time at 2016-02-27 19:34:03 UT. On 
our first (20s exposure)  set we  found 1 optical transient within SWIFT 
error-box (ra=12 59 08 dec=+78 38 19 r=0.050000) brighter then 17.6.


RA 12h 59m 14.13s
DEC +78d 40m 44.2s
  mag~17.36

The 5-sigma upper limit has been about 18.0
The message may be cited.


GRB_name: GRB160227A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19100
SUBJECT: GRB 160227A: Mt. Terskol observatory optical observation
DATE:    16/02/27 20:13:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev (Terskol Branch of INASAN), E. Mazaeva (IKI), V. Kozlov (IC 
AMER, NASU), A. Sergeev (Terskol Branch of INASAN), A. Pozanenko (IKI) 
report on behalf of larger GRB follow-up collaboration:

We observed the field of GRB 160227A (Siegel et al., GCN 19098) with 
Zeiss-600 telescope of Mt. Terskol observatory in R-filter starting on 
Feb. 27 (UT) 19:45:26. We obtained several images in R-filter. We 
clearly detect source in coordinates (J2000) 12 59 13.7 +78 40 44.9 
which is apparently the afterglow of GRB GRB 160227A (Siegel et al., GCN 
19098; Gorbovskoy et al., GCN 19099). The afterglow is clearly detected 
in a single images of 30 s exposure with brightness of ~19.0 magnitude 
in R-filter at Feb. 27 (UT) 19:49:36.


GRB_name: GRB160227A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19101
SUBJECT: GRB 160227A: ISON-Kislovodsk optical observation
DATE:    16/02/27 20:48:55 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Nevskiy (ISON), V. Vikhrov(ISON), K. Polyakov (ISON), N. Rudenko 
(IAON), A. Kalinichenko (ISON), E. Mazaeva (IKI), I. Molotov (KIAM), A. 
Pozanenko (IKI) report on  behalf of larger collaboration:


We observed the field of GRB 160227A (Siegel et al., GCN 19098) with
HGB-500  telescope (0.5-m, f/2) of ISON-Kislovodsk observatory  starting 
on Feb. 27 (UT) 19:38:53, i.e. ~400 s after burst trigger. We obtained 
several unfiltered images of 60 s exposure. We clearly detect  the 
afterglow of GRB 160227A (Siegel et al., GCN 19098; Gorbovskoy et al., 
GCN 19099; Andreev et al., GCN 19100). The afterglow brightness is 
~18.0 magnitude at Feb. 27 (UT) 19:38:53.


GRB_name: GRB160225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  19102
SUBJECT: GRB 160225A: TSHAO optical afterglow detection
DATE:    16/02/27 21:44:21 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Kusakin (Fesenkov Astrophysical Institute), I. Reva 
(Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) 
report on behalf of larger GRB follow-up collaboration:

We observed the Swift GRB 160225A (Siegel et al., GCN 19075) with 
Zeiss-1000 (West, East) 1-m telescopes of Tien Shan Astronomical 
Observatory. We obtained several images in R filter starting on Feb. 25 
(UT) 14:45:56. In the first images we do not detect any optical source 
(Mazaeva et al., GCN 19078). In combine images we detect afterglow 
(Yoshiiet al., GCN 19080; Kuroda  al., GCN 19081; Wiersema al., GCN 
19082).  Preliminary photometry of combined images is following

Date       UT start   t-T0    Filter  Exp.   OT     Err.  UL
                       (mid, days)     (s)

*2016-02-25 14:45:56   0.07022 R       87*90 20.75    0.16  21.4
  2016-02-25 15:30:59   0.09576 R       77*90 21.36    0.20  21.9
  2016-02-25 17:58:10   0.18146 R       52*90  n/d     n/a   21.7

*) Zeiss-1000 West telescope observations

Photometry is based on SDSS-DR9 nearby stars
SDSS-DR9_id            R(Lupton)
J105614.20+533500.1    15.35
J105714.63+533304.9    14.36
J105658.91+533304.1    15.77


