GRB111228A

This page lists all entries on GRB111228A in GRBweb

Summary Fermi GBM IPN Swift GCN 12737 GCN 12738 GCN 12741 GCN 12742 GCN 12743 GCN 12744 GCN 12745 GCN 12746 GCN 12747 GCN 12748 GCN 12749 GCN 12750 GCN 12751 GCN 12752 GCN 12753 GCN 12754 GCN 12756 GCN 12757 GCN 12758 GCN 12759 GCN 12760 GCN 12761 GCN 12763 GCN 12764 GCN 12765 GCN 12766 GCN 12767 GCN 12768 GCN 12769 GCN 12770 GCN 12771 GCN 12773 GCN 12778 GCN 12779 GCN 12784 GCN 12785 GCN 12787 GCN 12788 GCN 12789 GCN 12790 GCN 12791 GCN 12792 GCN 12798 GCN 12809 GCN 12832 GCN 12908 GCN 12918 GCN 13069

Summary table
Variable Value Source
GRB_name_Fermi GRB111228657
T0 15:44:41.394 UTC Fermi_GBM
ra 150.0667° Swift
decl 18.2977° Swift
pos_error 9.71e-05° Swift
T90 99.842 s Fermi_GBM
T90_error 2.111 s Fermi_GBM
T90_start 15:44:41.394 UTC Fermi_GBM
fluence 1.81e-05 erg/cm² Fermi_GBM
fluence_error 5.79e-08 erg/cm² Fermi_GBM
redshift 0.7140 GCN_circulars,Other
T100 102.806 s
GBM_located False
mjd 55923.65603465278 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB111228657
trigger_name bn111228657
ra 150.0650°
decl 18.2992°
pos_error 3.05e+00°
datum 2011-12-28
t_trigger 15:45:30.803 UTC
T90 99.842 s
T90_error 2.111 s
T90_start 15:44:41.394 UTC
fluence 1.81e-05 erg/cm²
fluence_error 5.79e-08 erg/cm²
flux_1024 2.08e+01 erg/cm²/s
flux_1024_error 4.24e-01 erg/cm²/s
flux_1024_time 7.36e+00 erg/cm²/s
flux_64 2.76e+01 erg/cm²/s
flux_64_error 1.74e+00 erg/cm²/s
IPN table
GRB_name GRB111228A
ra 150.0792°
decl 18.3000°
pos_error 5.00e-02°
redshift 0.7140
Swift table
GRB_name GRB111228A
t_trigger 15:44:43 UTC
ra 150.0667°
decl 18.2977°
pos_error 9.71e-05°
T90 101.2 s
fluence 8.50e-06 erg/cm²
redshift 0.7140
GCN 12737 table
GRB_name GRB111228A
GCN_number 12737
Detection_method Swift Det
t_trigger 15:44:43 UTC
ra 150.0790°
decl 18.2930°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12737 SUBJECT: GRB 111228A: Swift detection of a burst with an optical counterpart DATE: 11/12/28 16:00:13 GMT FROM: David Burrows at PSU/Swift T. N. Ukwatta (MSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), S. Campana (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Gendre (ASDC), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), H. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (NASA/GSFC), A. Melandri (INAF-OAB), J. P. Osborne (U Leicester), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team: At 15:44:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 111228A (trigger=510649). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 150.079, +18.293 which is RA(J2000) = 10h 00m 19s Dec(J2000) = +18d 17' 35" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a strong triple-peaked structure with a duration of about 100 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~93 sec after the trigger. The XRT began observing the field at 15:47:08.6 UT, 145.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 150.06478, 18.29912 which is equivalent to: RA(J2000) = 10h 00m 15.55s Dec(J2000) = +18d 17' 56.8" with an uncertainty of 4.2 arcseconds (radius, 90% containment). This location is 53 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 (2.95 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.4 (+2.09/-1.76) x 10^21 cm^-2 (90% confidence). The initial flux in the 0.1 s image was 8.82e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 155 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 10:00:16.01 = 150.06669 DEC(J2000) = +18:17:51.8 = 18.29773 with a 90%-confidence error radius of about 0.75 arc sec. This position is 8.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.19 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta 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.)
GCN 12738 table
GRB_name GRB111228A
GCN_number 12738
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12738 SUBJECT: GRB 111228A: Xinglong TNT confirms the optical afterglow DATE: 11/12/28 16:46:27 GMT FROM: L.P. Xin at NAOC L.P. Xin, J. Z. Li, J.Y. Wei, Y. L. Qiu, J. Wang, J.S. Deng, C. Wu, X. H. Han on behalf of EAFON report: We began to observe GRB 111228A (Ukwatta et al., GCN 12737) with Xinglong TNT telescope at 15:46:18 (UT), about 96 sec after the burst. A series of White, R-band images were obtained. The optical counterpart (Ukwatta et al., GCN 12737) was detected in all the images. The brightness of OT is about 16.5 magnitude at the mean time of 106 sec after the burst, relatively to USNO B1.0 catalogure. Follow-up observations are ongoing. This message may be cited. For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org:8080/grb/index.html"
GCN 12741 table
GRB_name GRB111228A
GCN_number 12741
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12741 SUBJECT: GRB 111228A: Possible host galaxy in the SDSS arhive DATE: 11/12/28 20:40:10 GMT FROM: Tolga Guver at UA Guver, T. (Sabanci Univ.) The field of the GRB 111228A (Ukwatta et al. GCN 12737) was observed with the SDSS survey (Abazajian et al. 2009, ApJS, 182, 543). Within 2.2 arcseconds of the XRT coordinates, SDSS detected a galaxy namely SDSS J100015.45+181755.1. The exact coordinates of the galaxy are given as RA : 150.06439037, DEC : +18.29865952 (J2000). SDSS magnitudes of the galaxy are : u = 21.99 +/- 0.20 g = 21.34 +/- 0.05 r = 20.90 +/- 0.05 i = 20.72 +/- 0.06 z = 20.72 +/- 0.21 SDSS also provides a photometric redshift for the galaxy as z = 0.192859 +/- 0.04821. For further information SDSS page for the galaxy is : http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237667734494445890 ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.
GCN 12742 table
GRB_name GRB111228A
GCN_number 12742
Detection_method Optical
ra 150.0647°
decl 18.2998°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12742 SUBJECT: GRB 111228A: TAROT Calern observatory. OT seems still bright DATE: 11/12/28 21:48:59 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (OHP-CNRS), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 111228A detected by SWIFT (trigger 510649) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The trigger occured during daytime over Calern. The observations started 289 min after the GRB trigger The elevation of the field increased from 7 degrees above horizon and weather conditions were good. We detect the candidate couterpart mentioned by Ukwatta et al. (GCNC 12737) and confirmed by Xin et al. (GCNC 12738) using a co-addition of 10 images of 3mins. Surprisingly, the OT is bright R~18 (Tstart=289 min, Tend=336 min) corresponding to an optical decay alpha~0.3 taken TNT and TAROT data. We suspect a rebrightening occured during the first minutes after the trigger. Netherveless, the low elevation and the 3 arcsec/pix sampling of TAROT does not allow to discriminate the OT from the star NOMAD1 1082-0210617 (RA=150.0646861 DEC=+18.2997694 R=19.9). Now TAROT continues observations in better airmass conditions but other observations are encouraged. This message may be cited.
GCN 12743 table
GRB_name GRB111228A
GCN_number 12743
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 12743 SUBJECT: GRB111228A: MITSuME Okayama Optical Observation DATE: 11/12/28 21:50:56 GMT FROM: Daisuke Kuroda at OAO/NAOJ 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 the MITSuME collaboration: We observed the field of GRB 111225A (Ukwatta et al., GCNC 12737) 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 2011-12-28 15:47:03 UT (~2.3 min after the burst). We detected the previously reported afterglow (Ukwatta, GCNC 12737; Xin et al., GCNC 12738) in all the three bands. Photometric results and are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err ---------------------------------------------------------------------- 0.00511 15:52:04 540.0 17.45 0.06 17.13 0.05 16.52 0.05 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 12744 table
GRB_name GRB111228A
GCN_number 12744
Detection_method Fermi GBM Det
t_trigger 15:45:30.800 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 12744 SUBJECT: GRB 111228A: Fermi GBM observation DATE: 11/12/28 23:03:23 GMT FROM: Michael S. Briggs at UAH and MSFC M. S. Briggs (UAH) and G. Younes (USRA) report on behalf of the Fermi GBM Team: "At 15:45:30.80 UT on 28 Dec 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 111228A (trigger 346779932 / 111228657), which was also detected by the Swift BAT/XRT/UVOT (Ukwatta et al. 2011, GCN 12737). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 70 degrees. The GBM light curve shows multiple peaks in three groups with a duration (T90) of about 100 s (50-300 keV) starting 50 seconds before the GBM trigger time. The time-averaged spectrum from T0+0 s to T0+57 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.9 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 34 +/- 4 keV A Band function fits the spectrum equally well with Epeak= 34 +/- 3 keV, alpha = -1.9 +/- 0.1 and beta = -2.7 +/- 0.3. The event fluence (10-1000 keV) in this time interval is 1.8E-5 erg/cm^2. The 64 ms peak photon flux measured starting from T0+7.7 s in the 10-1000 keV band is 27 +/- 1 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 12745 table
GRB_name GRB111228A
GCN_number 12745
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12745 SUBJECT: GRB 111228A, optical observations DATE: 11/12/29 00:09:07 GMT FROM: Shashi Bhushan Pandey at ROTSE S. B. Pandey, Vijay Kumar Bhatt, Brajesh Kumar and Ram Kesh Yadav (ARIES, NainiTal, India, on behalf of larger Indian GRB collaboration). We have observed GRB 111228A field (Ukwatta et al., GCN 12737; Briggs and Younes, GCN 12744) with the 1.04m telescope at ARIES NainiTal starting ~1.9 hours post-burst. Several sets of exposures varying 100s to 300 s each were taken in Bessel filters. The afterglow candidate (Xin et al., GCN 12738) is visible in individual frames. Preliminary photometry of the R_c band data in comparison to nearby USNO stars, indicates that the afterglow candidate has decayed by ~ 0.7 mag in ~ 3.5 hours of observations. This corresponds to a temporal decay index of ~ 0.3, similar to what has been noticed by Klotz et al. (GCN 12742). Further observations are continued. This message may be cited.
GCN 12746 table
GRB_name GRB111228A
GCN_number 12746
Detection_method Other
ra 150.0946°
decl 18.3232°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12746 SUBJECT: GRB 111228A: TAROT Calern observatory. OT decay stopped DATE: 11/12/29 00:14:59 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (OHP-CNRS), Atteia J.L. (IRAP-CNRS-OMP) report: We continue to obtain images of the field of GRB 111228A detected by SWIFT (trigger 510649) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France (cf. GCNC 12742). We confirm the OT observed by TAROT is not the galaxy mentioned by Guver (GCNC 12741) neither the object referenced as NOMAD1 1082-0210617 (Klotz GCNC 12742). The OT observed by TAROT is the afterglow of GRB 111228A and lies 9 arcsec eastern from these objects. As we previously announced (GCNC 12742), we confirm that the OT of GRB 111228A is brighter than a simple extrapolation of the very early observations using a standard decay. Current TAROT observations show that the decay is stopped. Unfiltered TAROT images were co-added to obtain a temporal series that shows clearly that the brightness remains almost constant since the beginning of the TAROT observations. Photometry is relative to the star NOMAD1 1083-0203467 (RA=150.0946028 DEC=+18.3231806 J2000) R=17.28 (V-R)=+0.69. Tstart Tend Rmag OT (min) (min) 289 318 18.6 +/- 0.4 321 352 18.9 +/- 0.4 358 389 18.5 +/- 0.3 392 421 18.7 +/- 0.3 429 459 18.7 +/- 0.3 462 492 18.9 +/- 0.3 This message may be cited.
GCN 12747 table
GRB_name GRB111228A
GCN_number 12747
Detection_method Swift-XRT Det
ra 150.0670°
decl 18.2978°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12747 SUBJECT: GRB 111228A: Enhanced Swift-XRT position DATE: 11/12/29 00:26:33 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1689 s of XRT Photon Counting mode data and 3 UVOT images for GRB 111228A, 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 = 150.06699, +18.29781 which is equivalent to: RA (J2000): 10h 00m 16.08s Dec (J2000): +18d 17' 52.1" with an uncertainty of 1.4 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.
GCN 12748 table
GRB_name GRB111228A
GCN_number 12748
Detection_method Optical
ra 150.0947°
decl 18.3233°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12748 SUBJECT: GRB 111228A: optical observations DATE: 11/12/29 01:07:55 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst V. Nascimbeni (Univ. Padova), E. Palazzi (INAF-IASFBo), D. Fugazza, A. Melandri, S. Covino (INAF-OABr), L. Borsato, A. Cunial, V. Granata (Univ. Padova), report on behalf of a larger collaboration: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with the 1.82m Asiago Telescope equipped with the AFOSC optical camera. A 900 s R-band image was acquired with mean time Dec 28.939 UT (6.79 hr after the burst trigger). We clearly detect the afterglow (Ukwatta et al., GCN 12737; Xin et al., GCN 12738; Klotz et al., GCN 12472) at a magnitude R = 18.6 +/- 0.02 assuming R = 17.28 for the star USNO-B1 1083-0199833 (RA = 10:00:22.72, Dec = +18:19:23.85 - same as used by Klotz et al., GCN 12746). We also clearly detect the SDSS object reported by Guver (GCN 12741), and confirm that it is not related to the GRB (Klotz et al., GCN 12746). Further observations are underway.
GCN 12749 table
GRB_name GRB111228A
GCN_number 12749
Detection_method Swift-BAT Det
ra 150.0630°
decl 18.2840°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12749 SUBJECT: GRB 111228A, Swift-BAT refined analysis DATE: 11/12/29 01:16:35 GMT FROM: Hans Krimm at NASA-GSFC J. R. Cummings (GSFC/UMBC),S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+746 sec from the recent telemetry downlink, we report further analysis of BAT GRB 111228A (trigger #510649) (Ukwatta, et al., GCN Circ. 12737). The BAT ground-calculated position is RA, Dec = 150.063, 18.284 deg which is RA(J2000) = 10h 00m 15.0s Dec(J2000) = +18d 17' 02.2" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted light curve shows multiple peaks in several clusters. The first set of peaks is at a low level from T-12 s to T+12 s. There is another low level set from T+32 to T+42 s, followed by a much brighter set of three overlapping peaks from T+45 to T+60 s. The final cluster is broad and relatively soft from T+85 to T+110 s. T90 (15-350 keV) is 101.20 +- 5.42 sec (estimated error including systematics). The time-averaged spectrum from T-12.82 to T+115.43 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.27 +- 0.06. The fluence in the 15-150 keV band is 8.5 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+54.56 sec in the 15-150 keV band is 12.4 +- 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/510649/BA/
GCN 12750 table
GRB_name GRB111228A
GCN_number 12750
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12750 SUBJECT: GRB 111228A: NOT optical observation DATE: 11/12/29 03:04:32 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS/NAOC), J. McCormac (Queen's Univ. Belfast), and P. Jakobsson (Univ. Iceland) report on behalf of a larger collaboration: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with the 2.5m Nordic Optical Telescope (NOT) equipped with the AFOSC optical camera. A 600s R-band image was taken with mean time 01:32 UT on 2011-12-29 (9.8 hr after the burst trigger). We clearly detected the afterglow (Ukwatta et al., GCN 12737; Xin et al., GCN 12738; Klotz et al., GCN 12742) at a magnitude R = 19.01 +/- 0.05, calibrated with the USNO-B1 1083-0199833 star (R2 = 17.28 mag; also used by Klotz et al., GCN 12746 and Nascimbeni et al., GCN 12748). Further observations are ongoing.
GCN 12751 table
GRB_name GRB111228A
GCN_number 12751
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12751 SUBJECT: GRB 111228A: Skynet/Dolomiti Optical Observations DATE: 11/12/29 03:51:36 GMT FROM: Melissa Nysewander at UNC-Chapel Hill M. Nysewander, J. Haislip, K. Ivarsen, A. LaCluyze, M. Maturi, D. Reichart, J. Moore, T. Cromartie, R. Egger, A. Foster, N. Frank, A. Oza, E. Speckhard, A.Trotter, and J. A. Crain report: Skynet observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with the 16" Dolomites Astronomical Observatory telescope (DAO) in Italy beginning 6.4 hrs after the burst, and lasting for one hour. We detect the afterglow in g' (11 x 180s) and r' (7 x 180s) exposures. Using ~20 SDSS field stars, we measure the OT to be g' = 19.4 +- 0.1 at 6.73 hours and r' = 19.3 +- 0.2 at 7.30 hours in stacked images. The OT faded by r' ~ 0.1 mag from 7.15 to 7.41 hours.
GCN 12752 table
GRB_name GRB111228A
GCN_number 12752
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 12752 SUBJECT: GRB 111228A: Swift/UVOT Detection DATE: 11/12/29 04:40:16 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (MSSL-UCL) and Ukwatta (MSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 111228A 155 s after the BAT trigger (Ukwatta et al., GCN Circ. 12737). The UVOT position is consistent with the enhanced XRT position (Goad et al., GCN Circ. 12747) within the measurement accuracy. 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 155 305 147 17.30 +/- 0.03 v 389 759 58 17.73 +/- 0.16 b 488 508 19 17.71 +/- 0.15 u 463 483 19 16.70 +/- 0.12 w1 439 459 19 16.59 +/- 0.17 m2 764 784 19 16.84 +/- 0.24 The preliminary lightcurves show achromatic behavior during the first 1200s and appears to maintain brightness levels until around 7000s after the trigger, when the decay in brightness sets in. The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN 12753 table
GRB_name GRB111228A
GCN_number 12753
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12753 SUBJECT: GRB 111228A: IAC80 BVI-band observations DATE: 11/12/29 05:10:43 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), R. Gimeno (IAC), A. Nicuesa Guelbenzu (TLS Tautenburg), report on behalf of a larger collaboration: "We observed the field of GRB 111228A (Ukwatta et al., GCNC 12737) with the 82cm IAC80 telescope at the Observatorio del Teide, Tenerife, Spain. The observations were carried in the BVI-bands on Dec 29.08662 - 29.19141 UT (10.3-12.8 hours post burst). The optical afterglow of the burst (Ukwatta et al., GCNC 12737; Xin et al., GCNC 12738; Klotz et al., GCNC 12742; Pandey et al. GCN 12745; Nascimbeni et al. GCNC 12748; Xu et al., GCNC 12750; Nysewander et al. GCN 12751; Kuin et al. GCN 12752) is well detected in the three bands with an approximate magnitude of I~18.5 with respect to the USNO B1.0 catalogue."
GCN 12754 table
GRB_name GRB111228A
GCN_number 12754
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12754 SUBJECT: GRB 111228A: GRAS017 optical observations DATE: 11/12/29 05:24:38 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report: GRAS 017 (Global-Rent-a-Scope, Nerpio, Spain) CDK17 17" (0.43 m) f/6.8 and FLI ProLine CCD camera were used to detect GRB 111228A optical afterglow 9.0 hours after the burst trigger. The observations were started at 2011-12-29 00:35:06 (UT) and stopped at 2011-12-29 00:58:26 (UT). Nine photometric R observations with 120s exposure times were made. The afterglow was detected at following position RA 10 00 16.07 and DEC +18 17 52.1. The following magnitude was obtained from the observations using USNO-B1 1083-0199853 (R2 = 17.28) as the comparison: Tmid(s)+T0 Filter Exp (sec) Mag Mag err Limit 32522 R 9x120 18.7 0.2 19.8 A png image of our observations is available at the following URL link: http://cutenews.kassiopeia.net/data/upimages/GRB111228A_web.png
GCN 12756 table
GRB_name GRB111228A
GCN_number 12756
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12756 SUBJECT: GRB 111228A: MASTER OT observations DATE: 11/12/29 07:29:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Sinykov, V.Yurkov, Yu.Sergienko, D.Varda, Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich, S. Shurpakov Sternberg Astronomical Institute, Moscow State University K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev,E.Konstantinov, Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka MASTER II robotic double telescope (MASTER-Net: http://observ.pereplet.ru) located in Blagoveschensk was pointed to the GRB111228.66 191 sec after notice time and 244 sec after GRB time at 2011-12-28 15:48:47.127 UT. The some delay was due to weather conditions. On our first (20s exposure, two polarizations, unfiltered) set we found optical transient at Swift OT position (Ukwatta et al., GCN Circ R12737). The OT magnitude is about 16.5 mag in both polarizations. The reduction is continuated. The message may be cited.
GCN 12757 table
GRB_name GRB111228A
GCN_number 12757
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 12757 SUBJECT: GRB 111228A: GROND observations DATE: 11/12/29 07:55:33 GMT FROM: Sylvio Klose at TLS Tautenburg A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2-m MPG/ESO telescope on La Silla. Observations started as soon the object was visible over La Silla, at 04:46 UT on December 29, about 13 hr after the burst. We detect the afterglow (Ukwatta et al., GCN 12737; Xin et al., GCN 12738) in all bands. At a mean time of December 29, 05:35 UT, in an 8min exposure, we measure the following preliminary magnitudes (AB system): g' = 20.17 +/- 0.01, r' = 19.84 +/- 0.01, i' = 19.67 +/- 0.02, z' = 19.50 +/- 0.03, J = 19.29 +/- 0.07, H = 18.93 +/- 0.08. The SED is best fit with a spectral slope of 0.90 +/- 0.05, with no evidence for additional extinction. Optical data are calibrated against SDSS and NIR data against 2MASS field stars. Observations are continuing.
GCN 12758 table
GRB_name GRB111228A
GCN_number 12758
Detection_method Optical
ra 150.0946°
decl 18.3232°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12758 SUBJECT: GRB 111228A: TAROT La Silla observatory observations DATE: 11/12/29 08:10:05 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (OHP-CNRS), Atteia J.L. (IRAP-CNRS-OMP) report: We continue to obtain images of the field of GRB 111228A detected by SWIFT (trigger 510649) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile (early observations were done using TAROT Calern, reported in GCNC 12742 and GCNC 12746). Photometry is relative to the star NOMAD1 1083-0203467 (RA=150.0946028 DEC=+18.3231806 J2000) R=17.28 (V-R)=+0.69. Tstart Tend Rmag OT (min) (min) 788 837 19.0 +/- 0.4 840 890 19.2 +/- 0.3 Taking account for the magnitudes obtained earlier from TAROT Calern we deduce that the plateau phase may be now finished and an optical decay of ~0.5 could now occur. This message may be cited.
GCN 12759 table
GRB_name GRB111228A
GCN_number 12759
Detection_method Other
redshift 0.7140
Circular_text TITLE: GCN CIRCULAR NUMBER: 12759 SUBJECT: GRB 111228A: MMT Redshift DATE: 11/12/29 08:16:27 GMT FROM: Edo Berger at Harvard J. Dittman, T. Laskar, and E. Berger (Harvard) report: "Starting on 2011 December 29.312 UT (15.7 hours after the burst) we used the Blue Channel spectrograph mounted on the MMT 6.5-m telescope to observe GRB111228A (GCN #12737). Our spectra cover the range 3400-8500A and reveal absorption lines of MgII and FeII at a common redshift of z=0.714, which we consider to be the redshift of GRB111228A. Additional observations are in progress."
GCN 12760 table
GRB_name GRB111228A
GCN_number 12760
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 12760 SUBJECT: GRB 111228A: PAIRITEL NIR Detection DATE: 11/12/29 08:18:18 GMT FROM: Adam Morgan at U.C. Berkeley GRB 111228A: PAIRITEL NIR Detection A. N. Morgan (UC Berkeley) reports: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2011-12-29 06:55:25 UT, ~15.2 hours after the Swift Trigger. In mosaics (effective exposure time of 0.46 hours) taken simultaneously in the J, H, and Ks filters, we marginally detect a source at the optical afterglow location (Ukwatta et al., GCN 12737; Xin et al., GCN 12738; Klotz et al., GCN 12742; Pandey et al., GCN 12745; Nascimbeni et al., GCN 12748; Xu et al. GCN 12750; Nysewander et al., GCN 12751; Kuin & Ukwatta, GCN 12752; Gorosabel et al., GCN 12753; Hentunen et al., GCN 12754; Sinykov et al., GCN 12756; Guelbenzu et al., GCN 12757). The preliminary photometry yields: post burst t_mid (hr) exp.(hr) filt mag m_err 15.56 0.46 J 18.3 0.2 15.56 0.46 H 17.8 0.3 15.56 0.46 Ks 16.2 0.3 All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values. Further observations are ongoing.
GCN 12761 table
GRB_name GRB111228A
GCN_number 12761
Detection_method Swift-BAT Det
redshift 0.7160
Circular_text TITLE: GCN CIRCULAR NUMBER: 12761 SUBJECT: GRB 111228A: Gemini South Redshift DATE: 11/12/29 08:25:14 GMT FROM: Antonino Cucchiara at LBNL A. Cucchiara (UCSC/UCO Lick), A. J. Levan (U. Warwick), and S. B. Cenko (UC Berkeley) report: We obtained spectroscopy of the optical afterglow of GRB 111228A (Ukwatta et al., GCN 12737) using GMOS-South on the Gemini-South 8-m telescope. Observations began on December 29.28 UT (15 hrs after the BAT trigger). Inspection of the first two exposures (range 4160-8140 Angstroms) reveals MgII2796,2803, MgII2853 and CaH&K absorption features at a common redshift of 0.716. We therefore suggest this to be the redshift of GRB 111228A. We thank the Gemini staff for performing this observation, in particular Pascale Hibon.
GCN 12763 table
GRB_name GRB111228A
GCN_number 12763
Detection_method Other
redshift 0.2180
Circular_text TITLE: GCN CIRCULAR NUMBER: 12763 SUBJECT: GRB111228A: TNG spectroscopy analysis DATE: 11/12/29 12:36:46 GMT FROM: Dino Fugazza at INAF-OAB E. Palazzi (INAF-IASFBo), D. Fugazza (INAF-OAB), S. Piranomonte (INAF-OAR) on behalf of a larger collaboration report: The afterglow of GRB 111228A (Ukwatta et al. GCN 12737) was observed with the DOLORES instrument mounted at the Telescopio Nazionale Galileo on La Palma, Canary Islands. Starting on December 29.1200 (~11 hour after the burst), a series of three spectra of 1800s each were secured with LR-B grism (range 3500-8000 Angstroms). Preliminary reduction of the spectra reveals absorption features that we identify with the following absorption lines: Lines ID Lambda_observed (Angstroms) FeII_2344.21 4019.83 FeII_2374.46 4073.40 FeII_2382.76 4088.32 FeII_2585.65 4436.05 FeII_2600.17 4460.64 MgII_2795.50 4795.65 MgII_2802.70 4808.58 MgI_2852.96 4891.53 CaII_3933.68 6756.61 CaII_3968.49 6807.44 The derived redshift is z=0.7156 0.0005 which confirms the results obatined by Dittman et al. (GCN 12759) and Cucchiara et al (GCN 12761). In addition to the GRB afterglow we observed the SDSS galaxy reported by Guver (GCN 12741). We detect many emission lines (OII_3726+3728, Hbeta, OIII_4958, OIII_5006, Halpha) at a common redshift of 0.218 0.001 which is in agreement with the reported photometric redshift. This galaxy is therefore not related to the GRB. We acknowledge the excellent support from the TNG staff, in particular Walter Boschin and Gianni Tessicini [GCN OPS NOTE(22jan12): Per author's request, the affilation was changed from "U.Milano-Bicocca,INAF/Brera" to "INAF-OAB".]
GCN 12764 table
GRB_name GRB111228A
GCN_number 12764
Detection_method Optical
redshift 0.7130
Circular_text TITLE: GCN CIRCULAR NUMBER: 12764 SUBJECT: GRB 111228A: NOT redshift DATE: 11/12/29 12:43:17 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS/NAOC), J.P.U. Fynbo (DARK), J. McCormac (Queen's Univ. Belfast), and P. Jakobsson (Univ. Iceland) report on behalf of a larger collaboration: We secured spectroscopy of the afterglow of GRB 111228A (Ukwatta et al., GCN 12737) with the 2.5m Nordic Optical Telescope (NOT) equipped with the ALFOSC optical camera. Observations started immediately after the 600s R-band photometry in Xu et al. (GCN 12750). The NOT spectrum covers 2750-9000A and shows clear absorption lines of MgII2803 and CaH&K, at a common redshift of z=0.713. Further observations are planned.
GCN 12765 table
GRB_name GRB111228A
GCN_number 12765
Detection_method Other
redshift 0.2180
Circular_text TITLE: GCN CIRCULAR NUMBER: 12765 SUBJECT: GRB111228A: TNG spectroscopy analysis DATE: 11/12/29 12:53:17 GMT FROM: Dino Fugazza at U.Milano-Bicocca,INAF/Brera E. Palazzi (INAF-IASFBo), D. Fugazza (INAF-OAB), S. Piranomonte (INAF-OAR) on behalf of a larger collaboration report: The afterglow of GRB 111228A (Ukwatta et al. GCN 12737) was observed with the DOLORES instrument mounted at the Telescopio Nazionale Galileo on La Palma, Canary Islands. Starting on December 29.1200 (~11 hour after the burst), a series of three spectra of 1800s each were secured with LR-B grism (range 3500-8000 Angstroms). Preliminary reduction of the spectra reveals absorption features that we identify with the following absorption lines: Lines ID Lambda_observed (Angstroms) FeII_2344.21 4019.83 FeII_2374.46 4073.40 FeII_2382.76 4088.32 FeII_2585.65 4436.05 FeII_2600.17 4460.64 MgII_2795.50 4795.65 MgII_2802.70 4808.58 MgI_2852.96 4891.53 CaII_3933.68 6756.61 CaII_3968.49 6807.44 The derived redshift is z=0.7156 +/- 0.0005 which confirms the results obatined by Dittman et al. (GCN 12759) and Cucchiara et al (GCN 12761). In addition to the GRB afterglow we observed the SDSS galaxy reported by Guver (GCN 12741). We detect many emission lines (OII_3726+3728, Hbeta, OIII_4958, OIII_5006, Halpha) at a common redshift of 0.218 +/- 0.001 which is in agreement with the reported photometric redshift. This galaxy is therefore not related to the GRB. We acknowledge the excellent support from the TNG staff, in particular Walter Boschin and Gianni Tessicini
GCN 12766 table
GRB_name GRB111228A
GCN_number 12766
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12766 SUBJECT: GRB 111228A: Swift-XRT refined Analysis DATE: 11/12/29 13:01:33 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo (INAF-OAB) and T. N. Ukwatta (MSU) report on behalf of the Swift-XRT team: We have analysed 6.4 ks of XRT data for GRB 111228A (Ukwatta et al. GCN Circ. 12737), from 135 s to 29.3 ks after the BAT trigger. The data comprise 331 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 12747). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=5.41 (+0.09, -0.07). At T+418 s the decay flattens to an alpha of 0.26 (+0.05, -0.06) before breaking again at T+6950 s to a final decay with index alpha=1.27 (+0.19, -0.15). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 4.16 (+0.12, -0.11). The best-fitting absorption column is 2.92 (+0.18, -0.17) x 10^21 cm^-2, in excess of the Galactic value of 3.0 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.19 (+0.11, -0.10) and a best-fitting absorption column of 1.52 (+0.27, -0.26) 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: 1.52 (+0.27, -0.26) x 10^21 cm^-2 Galactic foreground: 3.0 x 10^20 cm^-2 Excess significance: 7.9 sigma Photon index: 2.19 (+0.11, -0.10) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00510649. This circular is an official product of the Swift-XRT team.
GCN 12767 table
GRB_name GRB111228A
GCN_number 12767
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12767 SUBJECT: GRB 111228A: GMG optical observation DATE: 11/12/29 15:16:14 GMT FROM: Xiao-hong Zhao at Yunnan Observatory X.-H. Zhao (YNAO), D. Xu (WIS/NAOC), J.-R. Mao (KASI/YNAO), J.-M. Bai (YNAO) report: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) at the 2.4m Gao-Mei-Gu (GMG) telescope equipped with YFOSC. Observations started at 16:31:38 UT on 2011-12-28 (i.e., 47 mins after the burst) and 4x600s R-band images were obtained in a seeing of ~3.36". We found the afterglow was decaying. The results are as follows: mid time (UT) magnitude (err) 2011-12-28 16:36:38 17.11 (0.01) 2011-12-28 17:19:14 17.42 (0.01) 2011-12-28 17:44:57 17.56 (0.01) 2011-12-28 17:56:15 17.62 (0.01). The magnitudes were calibrated with the USNO-B1 #1083-0199833 star (R2 = 17.28 mag; also used by Klotz et al., GCN 12746; Nascimbeni et al., GCN 12748; Xu et al., GCN 12750; Hentunen et al., GCN 12754). Further observations are planned. We thank the GMG staff, especially Y.-X. Xin, Fen He, and Gui-Hua He for performing these observations. [GCN OPS NOTE(29dec11): Per author's request, the affiliation of X-H.Z. was changed to Yunnan Observatory.]
GCN 12768 table
GRB_name GRB111228A
GCN_number 12768
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 12768 SUBJECT: GRB111228A: MITSuME Akeno photometry of the optical afterglow DATE: 11/12/29 15:34:59 GMT FROM: Yoichi Yatsu at Tokyo Tech. R. Usui, Y. Aoki, S. Song, M. Hayashi, K. Kawakami, K. Tokoyoda, Y. Saito, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 111228A (Ukwatta et al., GCNC 12737) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2011-12-28 15:45:47 UT (~ 64 sec after the burst). We detected the previously reported afterglow (Ukwatta, GCNC 12737; Xin et al., GCNC 12738) in all the three bands. Photometric results and 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 ---------------------------------------------------------------------- 0.00074 15:46:02 30.0 17.3 0.2 16.12 0.09 15.5 0.1 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 12769 table
GRB_name GRB111228A
GCN_number 12769
Detection_method Swift Other
ra 150.0947°
decl 18.3233°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12769 SUBJECT: GRB 111228A: T100 observations DATE: 11/12/29 16:36:46 GMT FROM: Tolga Guver at UA T. Guver (Sabanci Univ.), E. Sonbas (Adiyaman Univ.), S. Kaynar (Akdeniz Univ.), E. Gogus (Sabanci Univ.), Z. Eker (TUG) report on behalf of a larger collaboration We observed the field of Swift GRB 111228A (Ukwatta et al., GCN 12737) with the 1.0 meter T100 telescope (TUBITAK National Observatory, Antalya - Turkey), starting December, 28, 22:48 UT (~ 7 hours after the trigger). Observations were carried out in the B, R, and V filters under good weather conditions. The afterglow is clearly detected in all images. Using the USNO-B1 star USNO-B1 1083-0199833 (RA = 10:00:22.72, Dec = +18:19:23.85 - same as used by Klotz et al., GCN 12746 and Nascimbeni et al., GCN 12748) in the field we estimated the following magnitudes for the OT: t - t0 (h) Exp. (s) Filter mag. err 6.859 300 B 19.12 +/- 0.04 6.958 300 B 19.56 +/- 0.07 8.219 300 B 19.58 +/- 0.04 8.317 300 B 19.39 +/- 0.05 7.057 300 R 18.45 +/- 0.02 7.155 300 R 18.50 +/- 0.02 8.416 300 R 18.58 +/- 0.02 8.514 300 R 18.61 +/- 0.03 We are grateful to the TUBITAK National Observatory staff for promptly scheduling the observations and their technical support. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.
GCN 12770 table
GRB_name GRB111228A
GCN_number 12770
Detection_method Other
redshift 0.7163
Circular_text TITLE: GCN CIRCULAR NUMBER: 12770 SUBJECT: GRB 111228A: X-shooter spectroscopy DATE: 11/12/29 19:19:59 GMT FROM: Steve Schulse at U. of Iceland S. Schulze (U Iceland), S. Covino (INAF-OABr), H. Flores (GEPI/Obs. de Paris), J. P. U. Fynbo (DARK/NBI), B. Milvang-Jensen (DARK/NBI), J. Sollerman (U Stockholm), D. Xu (WIS) report on behalf of the X-shooter GRB collaboration: We observed the afterglow of GRB 111228A (Ukwatta et al. GCN 12737) with the ESO VLT equipped with the X-shooter spectrograph on 29 December 2011, beginning 07:40 UT (15.93 hr after the GRB). The afterglow had an R-band brightness of 20.08 mag in a series of five acquisition images with an exposure time of 30 s each (mid-exposure time = 15.98 hours). The magnitude is not corrected for Galactic extinction. We acquired four spectra with an exposure time of 600 seconds each, beginning at 07:47 UT. We detect several absorption lines wave_obs wave_rest Ion redshift (AA, vac) (AA, vac) 3880.28 2260.78 FeII 0.71634 4023.15 2344.21 FeII 0.71620 4075.26 2374.46 FeII 0.71629 4089.47 2382.77 FeII 0.71627 4422.70 2576.88 MnII 0.71630 4439.44 2586.65 FeII 0.71629 4453.10 2594.50 MnII 0.71636 4462.57 2600.17 FeII 0.71626 4799.05 2796.35 MgII 0.71618 4811.32 2803.53 MgII 0.71616 4896.33 2852.96 MgI 0.71623 6753.24 3934.78 CaK 0.71630 6813.09 3969.59 CaH 0.71632 at a common redshift of z = 0.71627 +/- 0.00002. In addition we detect [OIII]5007 at z_em = 0.71635, similar to the absorption line redshift. Our measurements confirm the results by of Cucchiara et al (GCN 12761) and Palazzi et al (GCN 12763) and are similar to Dittmann et al (GCN 12759) and Xu et al (GCN 12764). The seeing conditions over the entire campaign were around 0.8 arcsec. We acknowledge the support of the VLT staff, in particular Claudio Melo and Christophe Martayan.
GCN 12771 table
GRB_name GRB111228A
GCN_number 12771
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12771 SUBJECT: GRB 111228A: P60 Observations DATE: 11/12/29 20:00:39 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration: We have imaged the field of GRB111228A (Ukwatta et al., GCN 12737) with the automated Palomar 60 inch telescope. Observations were obtained in the r' and i' filters beginning at 10:27 UT on 2011 December 29 (~ 18.9 hours after the Swift trigger). We detect the optical afterglow with a magnitude of r' = 20.3 +/- 0.1 mag (AB, calibrated with respect to several point sources from the Sloan Digital Sky Survey in the field). Compared with previous reported measurements of the afterglow brightness, this suggests a steeper decay than observed at early times (e.g., Klotz et al., GCN 12742). Further observations are planned.
GCN 12773 table
GRB_name GRB111228A
GCN_number 12773
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12773 SUBJECT: GRB 111228A: Liverpool Telescope Observations DATE: 11/12/29 21:14:20 GMT FROM: Carole Mundell at ARI, JMU,Liverpool A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), C. G. Mundell (Liverpool JMU) and N. R. Tanvir (U. Leicester), on behalf of a large collaboration report: "We observed the optical afterglow of GRB 111228A (Ukwatta et al., GCN 12737) with the 2-m Liverpool Telescope, starting at 02:55 UT on 2011 December 29. We took a sequence of images in Br'i' bands, with exposure time of 300s for each individual frame. We clearly detect the optical afterglow in all individual images. In stacked frames we find the following magnitudes for the OT: Mid time from Total Exp Filter Magnitude trigger (hr) (s) -------------------------------------------------- 12.08 4x300 r' 19.68 +- 0.06 13.28 3x300 r' 19.89 +- 0.09 12.54 5x300 i' 19.57 +- 0.05 11.34 4x300 B 19.71 +- 0.08 12.96 4x300 B 19.79 +- 0.11 -------------------------------------------------- The magnitudes are calibrated against nearby SDSS-5 (r' and i' bands) and USNO-B1.0 (B band) field stars and are not corrected for the Galactic extinction. This message may be cited."
GCN 12778 table
GRB_name GRB111228A
GCN_number 12778
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12778 SUBJECT: GRB111228A: Further GMG observations DATE: 11/12/30 04:04:44 GMT FROM: Xiao-hong Zhao at Yunnan Obs X.-H. Zhao (YNAO), L. P. Xin (NAOC), J.-R. Mao (KASI/YNAO), J.-M. Bai (YNAO) report on behalf of a larger collaboration: We made a further observation of GRB 111228A (Ukwatta et al., GCN 12737) with 2.4m Gao-Mei-Gu (GMG) telescope. Observations started at 16:07:37 UT on 2011-12-29 (i.e., ~24.4 hrs after the burst) . We found the afterglow has faded significantly. The magnitudes are as follows: mid time (UT) Exp. (s) Filter magnitude (err) 2011-12-29 16:12:37 600 R 20.24 (0.12) 2011-12-29 16:27:55 600 V 20.67 (0.18) 2011-12-29 16:38:54 600 B 21.13 (0.15) 2011-12-29 16:52:46 600 R 20.33 (0.12) 2011-12-29 17:03:24 600 V 20.73 (0.18) 2011-12-29 17:14:06 600 B 21.31 (0.16) 2011-12-29 17:28:50 600 R 20.54 (0.13) 2011-12-29 17:39:39 600 V 20.96(0.21) 2011-12-29 17:51:19 600 B 21.40 (0.17) The magnitudes were calibrated with the USNO-B1 #1083-0199833 star (R2 = 17.28 mag and (V-R)=+0.69; also used by Klotz et al., GCN 12746; Nascimbeni et al., GCN 12748; Xu et al., GCN 12750; Hentunen et al., GCN 12754; Klotz et al. GCN 12758). We thank the GMG staff, especially Y.-X. Xin, Fen He, and Gui-Hua He for performing these observations.
GCN 12779 table
GRB_name GRB111228A
GCN_number 12779
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12779 SUBJECT: GRB 111228A: Continued Skynet PROMPT/Dolomiti Optical Observations DATE: 11/12/30 04:32:27 GMT FROM: Aaron LaCluyze at U.North Carolina A. LaCluyze, M. Nysewander, J. Haislip, K. Ivarsen, M. Maturi, D. Reichart, J. Moore, T. Cromartie, R. Egger, A. Foster, N. Frank, A. Oza, E. Speckhard, A.Trotter, and J. A. Crain report: Skynet continued observing the field of GRB 111228A (Ukwatta et al., GCN 12737) with the PROMPT telescope array at CTIO in Chile and the 16" Dolomites Astronomical Observatory telescope (DAO) in Italy. We detect the afterglow in g', r', i' and B, R, I bands, with a chromatic variation suggested by late time data. A preliminary light curve, calibrated to SDSS catalog sources can be found at the following link: http://skynet.unc.edu/grb/grb111228a.png Further observations are ongoing to attempt to confirm or refute the chromatic variation.
GCN 12784 table
GRB_name GRB111228A
GCN_number 12784
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12784 SUBJECT: GRB 111228A: SMARTS optical/IR afterglow observations DATE: 11/12/30 17:34:16 GMT FROM: Bethany Cobb at GWU Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 111228A (GCN 12737, Ukwatta et al.) with a mid-exposure time of 15.9 hours (2011-12-29 07:39 UT) and 39.5 hours (2011-12-30 07:13 UT) post-burst. Total summed exposure times amounted to 36 minutes in I and 30 minutes in J. The optical afterglow of GRB 111228A (e.g. GCN 12737, Ukwatta et al.; GCN 12738, Xin et al.) is detected and observed to decay between our imaging. Preliminary comparison to Landolt standard stars in the optical and 2MASS stars in the IR indicates the following magnitudes for the afterglow: time post-burst I mag J mag 15.9 hours 19.3 +/- 0.1 20.6 +/- 0.1 39.5 hours 18.4 +/- 0.1 > 19.1 (3-sigma limit) This indicates that the decay rate of the burst between ~16 and 40 hours post burst is alpha ~ 1.3 (where afterglow flux is proportional to t^-alpha). In agreement with Cenko et al. (GCN 12771), this later-time decay is much steeper than the earlier-time decay noted by Klotz et al. (GCN 12742) and Pandey et al. (GCN 12745).
GCN 12785 table
GRB_name GRB111228A
GCN_number 12785
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 12785 SUBJECT: GRB 111228A: correction to GCN 12784 DATE: 11/12/30 17:52:34 GMT FROM: Bethany Cobb at GWU The data in the table in GCN 12784 was incorrectly placed. The corrected table is given below. time post-burst I mag J mag 15.9 hours 19.3 +/- 0.1 18.4 +/- 0.1 39.5 hours 20.6 +/- 0.1 > 19.1 (3-sigma limit) We apologize for any confusion. We thank Adam Miller for pointing out this error.
GCN 12787 table
GRB_name GRB111228A
GCN_number 12787
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12787 SUBJECT: GRB 111228A: Optical and NIR observations with Kanata telescope DATE: 11/12/31 01:04:46 GMT FROM: Michitoshi Yoshida at HASC,Hiroshima U R. Itoh, K. Takaki, M. Yamanaka, M. Sasada, K. Sakimoto, M. Yoshida, K. S. Kawabata, Y. Hanabata, M. Ohno, Y. Fukazawa (HiroshimaUniv.), A. Nakashima (Tokyo Univ.) report on behalf of the Kanata collaboration: We performed optical and near infrared observations of GRB 111228A (Ukwatta et al., GCN 12737; Xin et al., GCN 12738) with the 1.5 m Kanata Telescope of Higashi-Hiroshima observatory, Japan. The observation started at 15:47 UT on 2011 December 28. We took a sequence of images in Rc and K bands, and detected the optical-infrared afterglow of the GRB (Veli-Pekka Hentunen et al. GCN 12754; Kuroda et al. GCN 12743; Nicuesa Guelbenzu et al. GCN 12757; Usui et al. GCN 12768). Photometric results are listed below. We used USNO-B1 catalog for flux calibration of Rc band, and 2-MASS catalog for Ks band. Mid time from Total Exp Filter Magnitude trigger (hr) (s) ------------------------------------------------- 0.34 180x5 Ks 14.94 $B!^(B 0.10 1.12 300x10 Rc 17.67 $B!^(B 0.04 3.75 300x9 Rc 18.53 $B!^(B 0.02 -------------------------------------------------
GCN 12788 table
GRB_name GRB111228A
GCN_number 12788
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 12788 SUBJECT: GRB 111228A: correction for GCN 12787 DATE: 11/12/31 01:21:32 GMT FROM: Michitoshi Yoshida at HASC,Hiroshima U R. Itoh, K. Takaki, M. Yamanaka, M. Sasada, K. Sakimoto, M. Yoshida, K. S. Kawabata, Y. Hanabata, M. Ohno, Y. Fukazawa (HiroshimaUniv.), A. Nakashima (Tokyo Univ.) report on behalf of the Kanata collaboration: Character corruption occurred in the table of the Kanata telescope photometric results inthe GCN circular 12787. We resubmit the corrected table. We are sorry for the inconvenience. Mid time from Total Exp Filter Magnitude trigger (hr) (s) ------------------------------------------------- 0.34 180x5 Ks 14.94 +- 0.10 1.12 300x10 Rc 17.67 +- 0.04 3.75 300x9 Rc 18.53 +- 0.02 -------------------------------------------------
GCN 12789 table
GRB_name GRB111228A
GCN_number 12789
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12789 SUBJECT: GRB 111228A: MASTER-Net optical photometry DATE: 11/12/31 08:48:50 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka E. Sinykov, V.Yurkov, Yu.Sergienko, D.Varda, Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich, S. Shurpakov Sternberg Astronomical Institute, Moscow State University K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev,E.Konstantinov, Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory MASTER II robotic double telescope (MASTER-Net: http://observ.pereplet.ru) located in Blagoveschensk was pointed to the GRB111228A (Ukwatta et al., GCN Circ R12737) 191 sec after notice time and 244 sec after GRB time at 2011-12-28 15:48:47.127 UT (Sinykov et al., GCN Circ 12756). MASTER II robotic double telescope (MASTER-Net: http://observ.pereplet.ru) located near Kislovodsk was pointed to the GRB111228A ~6.5 hours after GRB time at 2011-12-28 22:24:47 UT. The results of our photometry are: Date UT Exp mag Err Filter Start (s) 2011-12-28 15:48:47.1 20 16.9 0.2 P| 2011-12-28 15:48:47.1 20 16.5 0.2 P- 2011-12-28 15:49:34.7 30 17.1 0.2 P| 2011-12-28 15:49:34.7 30 16.7 0.2 P- 2011-12-28 15:50:37.3 40 16.8 0.2 P| 2011-12-28 15:50:37.3 40 17.3 0.2 P- 2011-12-28 15:51:43.1 50 17.6 0.2 P| 2011-12-28 15:51:43.1 50 17.5 0.2 P- 2011-12-28 15:52:59.7 70 16.8 0.2 P| 2011-12-28 15:52:59.7 70 17.1 0.2 P- 2011-12-28 15:54:41.3 90 17.3 0.2 P| 2011-12-28 15:54:41.3 90 17.3 0.2 P- 2011-12-28 15:56:38.4 110 17.0 0.2 P| 2011-12-28 15:56:38.4 110 17.6 0.2 P- 2011-12-28 16:01:44.8 180 17.3 0.2 P| 2011-12-28 16:01:44.8 180 17.6 0.2 P- 2011-12-28 22:24:47.9 180 19.0 0.3 V 2011-12-28 22:24:47.9 180 18.3 0.3 R 2011-12-28 22:28:14.1 180 18.9 0.3 V 2011-12-28 22:28:14.1 180 18.8 0.3 R 2011-12-28 22:31:42.7 180 19.3 0.3 V 2011-12-28 22:31:42.7 180 18.6 0.3 R 2011-12-29 00:13:44.5 180 18.8 0.3 R 2011-12-29 00:17:12.7 180 19.4 0.3 R 2011-12-29 00:20:45.7 180 18.9 0.3 R 2011-12-29 00:20:45.7 180 19.5 0.3 V 2011-12-29 01:45:51.9 180 19.4 0.3 R 2011-12-29 01:52:48.1 180 18.7 0.3 R P|, P- - are the 2 polarisations in white The message may be cited.
GCN 12790 table
GRB_name GRB111228A
GCN_number 12790
Detection_method Konus-Wind Det
t_trigger 15:45:36.171 UTC
redshift 0.7150
Circular_text TITLE: GCN CIRCULAR NUMBER: 12790 SUBJECT: Konus-Wind observation of GRB 111228A DATE: 11/12/31 11:38:24 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 111228A (Swift-BAT trigger #510649: Ukwatta et al., GCN 12737; Cummings et al., GCN 12749) triggered Konus-Wind at T0=56736.171s UT (15:45:36.171). The light curve shows two groups of pulses separated by ~45 s. A total duration of the burst is ~50 s. The emission is seen up to ~1500 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB111228_T56736/ As observed by Konus-Wind the burst had a fluence of (7.5 1.3)x10-6 erg/cm2, and a 256-ms peak flux, measured from T0+3.584 s, of (2.0 0.3)x10-6 erg/cm2/s (both in the 20 keV - 2000 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+49.408 s) is best fit in the 20 keV - 2000 keV range by a simple power law function with the photon index of (2.4 0.2), chi2 = 53.7/62 dof. The spectrum at the maximum count rate (measured from T0 to T0+8.448 s) is also best fit in the 20 keV - 2000 keV range by a simple power law function with the photon index of (2.25 0.15), chi2 = 77.1/62 dof. Assuming the redshift z~0.715 (Dittman et al., GCN 12759; Cucchiara et al., GCN 12761; Palazzi et al., GCN 12765; Xu et al., GCN 12764) and a standard cosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the isotropic energy release E_iso is (1.0 0.2)x10^52 erg, and the isotropic peak luminosity L_iso_max is (4.6 0.7)x10^51 erg/s. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.
GCN 12791 table
GRB_name GRB111228A
GCN_number 12791
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 12791 SUBJECT: GRB 111228A: LOAO Optical Observation DATE: 11/12/31 11:58:29 GMT FROM: Myungshin Im at Seoul Nat U Yiseul Jeon, Myungshin Im, Minsung Jang (CEOU/Seoul National Univ.), and Yuji Urata (NCU) on behalf of a larger collaboration We observed GRB 111228A (Ukwatta et al., GCN 12737) in B- and R-bands with a 1 m telescope at Mt. Lemmon, Arizona, US. The observation started at 2011-12-30 08:03:16 UT, or 1.7 days after the BAT aleart. We detected the afterglow in the images taken with both filters. Using the the photometry calibration based on an USNO B1 star USNO-B1 1083-0199833 with B=18.85 and R=17.28 following Klotz et al. (GCN 12746), we find the following. Filter Mid-Time[UT] Mid-Time[Since BAT] Mag B-band 2011-12-30 08:33:55 40.82 hours 21.75+-0.14 R-band 2011-12-30 10:41:29 42.95 hours 20.67+-0.09 Further observation is ongoing. We thank the LOAO operator, J. Yoon for his help with the observation.
GCN 12792 table
GRB_name GRB111228A
GCN_number 12792
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12792 SUBJECT: GRB 111228A, optical observations DATE: 11/12/31 12:19:21 GMT FROM: Shashi Bhushan Pandey at ROTSE S. B. Pandey, R. K. S. Yadav, Ram Sagar (ARIES, NainiTal, India) and C. S. Stalin (IIA, Bangaluru); on behalf of larger Indian GRB collaboration. The newly installed 1.3m Devasthal Fast Optical Telescope (79.7 E, 29.4 N, altitude ~ 2450 m) started looking towards the Swift trigger 510649 (Ukwatta et al., GCN 12373) ~ 2.7 hours after the burst. The optical afterglow candidate (Ukwatta et al., GCN 12373; Xin et al., GCN 12738) was clearly detected in the individual frames with an exposure time of 120 sec each, taken in R_c band. The decaying afterglow (Klotz et al., GCN 12742; Pandey et al., GCN 12745; Cenko et al., GCN 12771) was also detected during the observations taken on consecutive night in the frames having exposure time of 300 sec each. Preliminary photometry of the frames yields following. Time (UT) Exp (s) Filter Magnitude ------------------------------------------------------------- 2011-12-28,18:30:46.0 120 s R_c 18.1+/-0.1 2011-12-29,23:56:38.0 300 s R_c 19.8+/-0.1 ------------------------------------------------------------- The magnitudes are calibrated against nearby USNO stars. Further observations are continued. This massage may be cited.
GCN 12798 table
GRB_name GRB111228A
GCN_number 12798
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12798 SUBJECT: GRB 111228A: optical observations in CrAO DATE: 12/01/02 14:52:27 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 111128A (Ukwatta et al. GCN 12737) with Shajn telescope of CrAO observatory between (UT) 2011-12-28T23:08:08 and 2011-12-29T01:04:41 under a mean seeing of 1.5". We took several frames with exposure of 60 s in BVRI. The photometry optical afterglow (Ukwatta et al. GCN 12737; Xin et al. GCN 12738) is based on the USNO B1.0 star 1083-0199833 (10 00 22.70 +18 19 23.5) assuming B=18.85, R=17.28, I=17.02 . T0+ Filter, Exposure, OT, uplim (3 sigma) (mid, d) (s) 0.3476 B 27x60 19.270 +/- 0.007 23.6 0.3491 R 27x60 18.710 +/- 0.005 23.5 0.3499 I 27x60 18.608 +/- 0.006 23.2
GCN 12809 table
GRB_name GRB111228A
GCN_number 12809
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12809 SUBJECT: GRB111228A :LOAO R-band Observations DATE: 12/01/06 02:50:13 GMT FROM: Yiseul Jeon at SNU/CEOU Minsung Jang, Myungshin Im, Yiseul Jeon (CEOU/Seoul National Univ.), and Yuji Urata (NCU) on behalf of a larger collaboration We continued our observation (Jeon et al. GCN 12791) of GRB 111228A (Ukwatta et al., GCN 12737) in R-band with a 1 m telescope at Mt. Lemmon, Arizona, US. Data were taken at 2011-12-31 UT and 2012-01-01 UT. For both of them, we detected the afterglow in stacked R-band images. We used a USNO B1 star near the afterglow, USNO-B1 1083-0199833 with R=17.28 following Klotz et al. (GCN 12746) for our photometry calibration, and current, rough estimates are given below. Mid-time [UT] | Mid-time[Since BAT] | Exptime [sec] | R-magnitude | ------------------------------------------------------------------------------------------------------------- 2011-12-31 08:40:25 | 64.92 hours | 300sec X 7 | 21.5 +/- 0.28 | 2012-01-01 11:19:52 | 91.58 hours | 300sec X 9 | 22.3 +/- 0.36 | We thank the LOAO operator, J. Yoon for his help with these observations.
GCN 12832 table
GRB_name GRB111228A
GCN_number 12832
Detection_method Optical
ra 150.0946°
decl 18.3232°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12832 SUBJECT: GRB 111228A: optical observations DATE: 12/01/14 12:00:43 GMT FROM: Alina Volnova at SAI MSU A. Volnova (SAI MSU), L. Elenin (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with 0.45-m telescope of ISON-NM observatory on Dec. 29 at 11:55 (UT, middle of exposure) in R band with mean FWHM of about 4.9". We took several unfiltered frames with exposure of 60 s. In a stacked image we detect an optical counterpart (Ukwatta et al., GCN 12737; Xin et al., GCN 12738). The photometry is based on the USNO-B1.0 star 1415-0025726 (RA = 10:00:22.70 Dec = +18:19:23.4, J2000) assuming R2 = 17.28: T0+, Filter, Exposure, OT (mid, d) (s) 0.84102 R 1800 19.27+/-0.12
GCN 12908 table
GRB_name GRB111228A
GCN_number 12908
Detection_method Swift-UVOT Other
ra 150.0668°
decl 18.2978°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12908 SUBJECT: GRB 111228A: Possible host detected by Swift/UVOT DATE: 12/02/02 21:57:17 GMT FROM: Paul Kuin at MSSL Paul Kuin (MSSL/UCL) and Tilan Ukwatta (MSU) reports on behalf of the Swift UVOT Team: Until recently, Swift UVOT continued observations in multiple filters of GRB 111228A (Ukwatta et al., GCN Circ. 12737). Based on the observations taken up to January 31, 2012 in the white filter, a possible host is detected. The UVOT position in decimal degrees of the GRB during the early and peak emission period is: RA=150.06684 DEC=+18.297834, J2000 (sexagesimal 10:00:16.04, +18:17:52.20), consistent with the enhanced XRT position reported in GCN Circ. 12747 by Goad et al.. The position of the late time emission/possible host is: RA=150.06643 DEC=+18.297903, J2000 (sexagesimal 10:00:15.94, +18:17:52.45). The position of the late-time emission is offset by 0.9" which is significantly larger than the position error for a single uvot image of 0.5" (Breeveld et al., 2010, MNRAS 406, 1587), and the unknown smaller position error when comparing between summed UVOT images. The offset suggests that the late-time emission is due to a different source, possibly the host. Other evidence comes from a late time flattening of the light curve. The late time count-rate light curve decays with a power index of -1.3 in nearly all bands. Taking that as the decay rate, the light curves in white and uvw2 deviate at times more than 800ks after the trigger. Extrapolating the power law decay and subtracting from the late-time white count rate, we estimate a host magnitude in white = 24.6 (+0.4/-0.6) mag, which corresponds to a host flux in the broadband white filter of (2.05+/-0.8)x10^-7 Jy (3471 A).
GCN 12918 table
GRB_name GRB111228A
GCN_number 12918
Detection_method Other
ra 150.0670°
decl 18.2978°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12918 SUBJECT: GRB 111228A, the review of the sky area in plate archives DATE: 12/02/08 09:52:41 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv V.V.Golovnya (Main Astro Obs, Kyiv) report: We have undertaken the review of the sky area in vicinity of GRB 111228 (M.R. Goad et al. GCN Circ.12747) on astronegatives, collected in Ukrainian NAS Main astronomical observatory plate archive (1976-1996). All the plates with the possible object appearance are digitized using Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL flatbed scanners and have been placed into Golosiiv Plate Archive database DBGPA with open access to them. The list of plates is given in the table: YYYYMMDD/TimeUT --Plates-- Exp. LimMag Star USNOA2 19900323/192716 GUA040C003372 14.5 15.05 1050-06177767 19920228/213449 GUA040C001967A 20.0 15.60 1050-06179692 19921201/032302 GUA040C002052A 18.0 15.05 1050-06177767 19921218/022500 GUA040C002075A 21.0 15.05 1050-06177767 19930211/220606 GUA040C002118 22.0 15.60 1050-06179692 19930314/204336 GUA040C002155 20.0 15.60 1050-06179692 Plates: the plates archive identifier of DWA (D/F=400/2000, GUA040C M=103"/mm) of the Ukrainian NAS Main Astro obs. (Marsden's number - 83) the plate number [1]. Exp. - Duration of the maximum exposure (minutes). LimMag - Limited V mag, derived in the 23 minutes area around the location given in M.R. Goad et al. GCN Circ. 12747: RA(J2000) = 10h 00m 16.08s, Dec(J2000) = +18d 17'52.1" Star USNOA2 - Comparison star. The preview images of 6 areas together with the 23x23 min.of arc area from SkyMap can be found in http://gua.db.ukr-vo.org/img/grb/111228A/index.html The images with full resolution are available via e-mail on demand. References: 1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), http://gua.db.ukr-vo.org
GCN 13069 table
GRB_name GRB111228A
GCN_number 13069
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 13069 SUBJECT: GRB 111228A: possible detection of the SN with the TNG DATE: 12/03/16 13:03:08 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, A. Melandri (INAF-OAB), E. Palazzi (INAF-IASF Bo), S. Campana (INAF-OAB), M. Della Valle (INAF-OAC), E. Pian (INAF-OATs), R. Salvaterra (INAF-IASF Mi), G. Tagliaferri (INAF-OAB) report on behalf of the CIBO collaboration: We observed the optical counterpart of GRB 111228A (Ukwatta et al., GCN 12737) with the Italian 3.6m TNG telescope on 2012 Feb 1.16 UT (34.5 days post burst) and March 13.91 UT (76.2 days post burst). Observations were carried out in the R and I bands. The counterpart is well detected in the two epochs in both filters, with a magnitude R = 24.3 in the March observation (calibrated using Landolt standard stars). The late value is likely dominated by the host galaxy. Differential photometry reveals that the source faded between the two epochs by 0.4 +/- 0.2 and 0.9 +/- 0.1 mag in the R and I band, respectively. The observed fading indicates that a transient component was present during our February observation. This could be due to residual afterglow emission, or to the presence of an emerging supernova (SN). After subtracting the host galaxy flux, the color of the transient on February 1 is very red, with R-I ~ 2. This color is not typical of GRB afterglows, and is much redder than measured at early times for this object (e.g., r'-i' = 0.17 AB at t = 0.57 days: Nicuesa Guelbenzu et al., GCN 12757). Such a red spectrum, on the contrary, is consistent with that of a type-Ic SN at z=0.72 (e.g., Dittman et al., GCN 12759), since the observed R band corresponds to the rest-frame U, where severe line blanketing suppresses the SN flux. Also, the I-band magnitude of the transient is comparable to that of SN 1998bw close to the peak of luminosity, placed at z=0.72. Although a more accurate analysis of the afterglow behaviour is necessary, based on the above arguments, we believe to have detected the emission from the SN associated with GRB 111228A. We acknowledge the TNG staff for their support, in particular Luca Di Fabrizio and Daniele Carosati.