| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB141230142 |
|
| T0 |
3:24:22.637 UTC |
Fermi_GBM |
| ra |
56.9800° |
Fermi_GBM |
| decl |
1.5900° |
Fermi_GBM |
| pos_error |
2.74e+00° |
Fermi_GBM |
| T90 |
9.856 s |
Fermi_GBM |
| T90_error |
1.086 s |
Fermi_GBM |
| T90_start |
3:24:22.637 UTC |
Fermi_GBM |
| fluence |
1.80e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
6.62e-08 erg/cm² |
Fermi_GBM |
| T100 |
9.856 s |
|
| GBM_located |
True |
|
| mjd |
57021.14192866898 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB141230142 |
| trigger_name |
bn141230142 |
| ra |
56.9800° |
| decl |
1.5900° |
| pos_error |
2.74e+00° |
| datum |
2014-12-30 |
| t_trigger |
3:24:22.637 UTC |
| T90 |
9.856 s |
| T90_error |
1.086 s |
| T90_start |
3:24:22.637 UTC |
| fluence |
1.80e-06 erg/cm² |
| fluence_error |
6.62e-08 erg/cm² |
| flux_1024 |
8.40e+00 erg/cm²/s |
| flux_1024_error |
4.02e-01 erg/cm²/s |
| flux_1024_time |
6.40e-02 erg/cm²/s |
| flux_64 |
9.57e+00 erg/cm²/s |
| flux_64_error |
1.95e+00 erg/cm²/s |
| GCN 17254 table |
|---|
| GRB_name |
GRB141230A |
| GCN_number |
17254 |
| Detection_method |
iPTF |
| ra |
62.1728° |
| decl |
-6.6767° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 17254
SUBJECT: GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
DATE: 14/12/30 08:28:03 GMT
FROM: Leo Singer at CIT/PTF
L. P. Singer (NASA/GSFC), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal
(Carnegie Observatories/Princeton) report on behalf of the intermediate
Palomar Transient Factory (iPTF) collaboration:
Fermi GBM detected GRB 141230A (Fermi trigger 441602665 / bn141230142) at
2014-12-30 03:24:22.64. We searched for optical counterparts using the
Palomar 48-inch Oschin telescope (P48), imaging 20 fields spanning an area
of 147 deg2, covering about half of the 1-sigma statistical+systematic
region of the final Fermi GBM localization and part of the 2-sigma region.
Based on the GBM localization, we estimate a 43% 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 detect the optical transient
iPTF14jko, at the coordinates:
RA(J2000) = 4h 08m 41.48s (62.172836 deg)
Dec(J2000) = -6d 40' 36.0" (-6.676663 deg)
No source is detectable at this location in SDSS images. The last iPTF
survey visit was on September 16. We report the following P48 photometry:
-104.7 day: R > 20.12
+54.80 min: R = 19.91 +/- 0.11
+129.9 min: R = 19.75 +/- 0.14
The source does not appear to be fading at this time. Times are relative
to 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 also detect the optical transient iPTF14jkn, at the coordinates:
RA(J2000) = 3h 55m 02.59s (58.760779 deg)
Dec(J2000) = -6d 44' 04.2" (-6.734503 deg)
We note that this position is near the bright (r = 13.59 mag) star,
SDSS J035501.84-064404.9. We report our P48 photometry:
-104.7 day: R > 20.34
+98.02 min: R = 19.60 +/- 0.10
Poor seeing conditions may call into question the veracity of this optical
transient and the accuracy of its photometry.
We have submitted a Swift TOO for iPTF14jko. Further observations are
encouraged to determine the nature of the source.
The diagram http://www.its.caltech.edu/~lsinger/iptf/Fermi441602665.pdf
shows our P48 fields and the location of the optical transient candidates
in relation to the Fermi GBM 1- and 2-sigma statistical+systematic
contours.
|
| GCN 17255 table |
|---|
| GRB_name |
GRB141230A |
| GCN_number |
17255 |
| Detection_method |
Optical |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 17255
SUBJECT: GRB 141230A: Nanshan optical obsrvations
DATE: 14/12/30 15:36:22 GMT
FROM: Dong Xu at DARK/NBI
D. Xu (DARK, NAOC), H.-B. Niu, A. Esamdin, L. Ma (XAO) report:
We observed the field of iPTF14jko (Singer et al., GCN 17254), a
candidate optical afterglow of GRB 141230A (Fermi trigger 441602665 /
bn141230142), using the 1m telescope located at Nanshan, Xinjiang,
China. We obtained 2x120s R-band images at 13:40 UT on 2014-12-30
(i.e., ~10.3 hr post-burst).
A source is detected at the iPTF14jko position with m(R)=19.53+/-0.28
(Vega), calibrated with nearby SDSS stars. The source basically
remains constant compared with the early (129.9 min post-burst)
measurement in GCN 17254, which indicates that it is unlikely the
optical afterglow of GRB 141230A, according to the decaying behavior
of conventional GRB optical light curves.
|
| GCN 17257 table |
|---|
| GRB_name |
GRB141230A |
| GCN_number |
17257 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
3:24:22.640 UTC |
| ra |
57.0000° |
| decl |
1.6000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 17257
SUBJECT: GRB 141230A: Fermi GBM detection
DATE: 14/12/30 19:13:43 GMT
FROM: Oliver Roberts at UCD/Fermi
O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team:
"At 03:24:22.64 UT on the 30th of December 2014, the Fermi
Gamma-Ray Burst Monitor triggered and located GRB 141230A
(trigger 441602665 / 141230142 ). The GBM on-ground location,
using the Fermi GBM trigger data, is RA = 57.0, Dec =+1.6,
with an uncertainty of 3.3 degrees (radius, 1-sigma
containment,statistical only; there is additionally a
systematic error which is currently estimated to be 2 to
3 degrees).
The angle from the Fermi LAT boresight is about 120 degrees.
The GBM light curve consists of a single FRED-like peak with
a duration (T90) of about 9.9 s (50-300 keV). The time-averaged
spectrum from T0+0.0 s to T0+5.1 s is well fit by a power law
function with an an exponential high-energy cutoff. The power
law index is -1.51 +/- 0.19 and the cutoff energy, parameterized
as Epeak, is 75 +/- 16 keV. The event fluence (10-1000 keV) in
this time interval is (1.2 +/- 0.1)E-06 erg/cm^2. The 1-sec peak
photon flux measured starting from T0+0.1 s in the 10-1000 keV
band is 8.4 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|
| GCN 17258 table |
|---|
| GRB_name |
GRB141230A |
| GCN_number |
17258 |
| Detection_method |
Swift-XRT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 17258
SUBJECT: Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
DATE: 14/12/30 23:26:05 GMT
FROM: Andrea Melandri at INAF-OAB
A. Melandri, M.G. Bernardini, P. DAvanzo (INAF-OAB), F. E. Marshall (NASA/GSFC), P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift team:
We have analysed 3 ks of Swift-XRT data for the optical transient iPTF14jko (Singer et al., GCN 17254) within the error circle of the Fermi/GBM GRB 141230A (Roberts, GCN Circ. 17257), from 29.2 ks to 41.9 ks after the GBM trigger. The data are all in Photon Counting (PC) mode. No X-ray afterglow is detected at the position of the iPTF14jko optical source reported by Singer et al. (GCN Circ 17254). The 3-sigma upper limit is 3.3 x 10^-3 cts/s.
The Swift-UVOT began settled observations of the field of GRB 141230A about 29.2 ks after the GBM trigger. No optical afterglow consistent with the optical position (Singer et al. GCN Circ. 17254) is detected in the initial UVOT exposures.The preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures is:
Filter T_start(s) T_stop(s) Exp(s) Mag
w2 29202 41957 2928 >21.8
The magnitude in the table is 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).
|