GRB131231A

This page lists all entries on GRB131231A in GRBweb

Summary Fermi GBM IPN Fermi LAT GCN 15640 GCN 15641 GCN 15642 GCN 15643 GCN 15644 GCN 15645 GCN 15646 GCN 15647 GCN 15648 GCN 15650 GCN 15652 GCN 15670 GCN 15672 GCN 15673 GCN 15676 GCN 15680 GCN 15681 GCN 15711

Summary table
Variable Value Source
GRB_name_Fermi GRB131231198
T0 4:45:16.080 UTC Fermi_LAT
ra 10.5903° Fermi_LAT
decl -1.6529° Fermi_LAT
pos_error 8.30e-05° Fermi_LAT
T90 31.232 s Fermi_GBM
T90_error 0.572 s Fermi_GBM
T90_start 4:45:29.395 UTC Fermi_GBM
fluence 1.52e-04 erg/cm² Fermi_GBM
fluence_error 1.19e-07 erg/cm² Fermi_GBM
redshift 0.6420 GCN_circulars,Optical
T100 44.547 s
GBM_located False
mjd 56657.19810277778 Fermi_LAT
Fermi GBM table
GRB_name_Fermi GRB131231198
trigger_name bn131231198
ra 10.5900°
decl -1.6500°
pos_error 2.47e+00°
datum 2013-12-31
t_trigger 4:45:16.083 UTC
T90 31.232 s
T90_error 0.572 s
T90_start 4:45:29.395 UTC
fluence 1.52e-04 erg/cm²
fluence_error 1.19e-07 erg/cm²
flux_1024 7.88e+01 erg/cm²/s
flux_1024_error 6.55e-01 erg/cm²/s
flux_1024_time 2.24e+01 erg/cm²/s
flux_64 8.27e+01 erg/cm²/s
flux_64_error 2.68e+00 erg/cm²/s
IPN table
GRB_name GRB131231A
ra 10.5833°
decl -1.8500°
pos_error 1.50e-01°
redshift 0.6420
Fermi LAT table
GRB_name_Fermi GRB131231198
GRB_name GRB131231A
MET 410157919.08
datum 2013-12-31
t_trigger 4:45:16.080 UTC
ra 10.5903°
decl -1.6529°
pos_error 8.30e-05°
GCN 15640 table
GRB_name GRB131231A
GCN_number 15640
Detection_method Fermi LAT Det
t_trigger 4:45:16.080 UTC
ra 10.5850°
decl -1.8450°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15640 SUBJECT: GRB 131231A: Fermi-LAT detection of a burst DATE: 13/12/31 18:38:00 GMT FROM: Eda Sonbas at NASA/GSFC E. Sonbas (Adiyaman Univ.), J. L. Racusin (NASA/GSFC), D. Kocevski (NASA/GSFC) and J. McEnery (NASA/GSFC), report on behalf of the Fermi-LAT team: At 04:45:16.08 on Dec 31, 2013, Fermi LAT detected high energy emission from GRB 131231A, which was also detected by Fermi-GBM (trigger 410157919/131231198). The best LAT on-ground location is found to be RA, Dec 10.585, -1.845 (J2000) with an error radius of 0.149 deg (90% containment, statistical error only), this was 40 deg from the LAT boresight at the time of the trigger. The GRB was detected at high enough peak flux in the GBM detectors to trigger an autonomous repoint of the spacecraft, which kept the source in the LAT field of view for 900 seconds. The data from the Fermi LAT are temporally correlated with the GBM emission with high significance. More than 37 photons above 100 MeV and more than 11 photons above 1 GeV are observed within 900 seconds. The highest energy photon is a 9.7 GeV event which is observed at 700 seconds after the GBM trigger. A Swift ToO request has been submitted. The Fermi LAT point of contact for this burst is Eda Sonbas ( edasonbas@yahoo.com). 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.
GCN 15641 table
GRB_name GRB131231A
GCN_number 15641
Detection_method Other
ra 10.5850°
decl -1.8450°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15641 SUBJECT: GRB 131231A: Nanshan afterglow candidate DATE: 13/12/31 21:39:24 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), H.-B. Niu, X. Zhang, A. Esamdin, L. Ma (XAO) report: We observed the LAT field of GRB 131231A (Sonbas et al., GCN 15640) using the 1m telescope located on Mt. Nanshan, Xinjiang, China, equipped with a 1.2x1.2 deg^2 CCD camera. We obtained a series of 120s and 300s frames at the mean time 12:40 UT on 2013-12-31 (i.e., 7.91 hr after the Fermi trigger). Within the LAT error circle (RA, Dec 10.585, -1.845 with an error radius of 0.149 deg, error statistical only) reported in Sonbas et al. (GCN 15640), no new prominent uncatalogued source is found and the depth of the Nanshan image is similar to that of DSS II. Given that the above LAT error is statistical only, we thus inspect that surrounding region the LAT error circle and discovered a bright source, not present in both DSS II and SDSS, at coordinates R.A.=00:42:21.66 Dec.=-01:39:10.79 Err Radius: ~1.5 arcsec with a magnitude of R~17.6, calibrated with nearby USNO B1 stars. Follow-up observations are encouraged to check whether the source is the afterglow of the burst.
GCN 15642 table
GRB_name GRB131231A
GCN_number 15642
Detection_method Other
ra 10.5903°
decl -1.6529°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15642 SUBJECT: GRB 131231A: afterglow confirmation from the NOT DATE: 13/12/31 23:02:02 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani, D. Xu (DARK/NBI), I. R. Losada (Stockholm), F. Duval (Stockholm), report on behalf of a larger collaboration: We observed the afterglow candidate of GRB 131231A (Sonbas et al., GCN 15640; Xu et al., GCN 15641) using the 2.56m Nordic Optical Telescope (NOT) equipped with MOSCA. Observations started at 22:05:40 UT on 2013 Dec 31 (i.e., 17.3 hr after the Fermi trigger). The afterglow candidate noted by Xu et al. (GCN 15641) has decayed to R=18.6, using the same calibration. We thus suggest that this source is very likely the afterglow of GRB 131231A. The coordinates of the afterglow can be refined to R.A. = 00:42:21.665 Dec. = -01:39:10.61 with an error of 0.3". We also wish a happy new year to everyone.
GCN 15643 table
GRB_name GRB131231A
GCN_number 15643
Detection_method Optical
ra 10.5903°
decl -1.6531°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15643 SUBJECT: GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection DATE: 13/12/31 23:07:42 GMT FROM: Leo Singer at CIT/PTF L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal (Carnegie Observatories) report on behalf of the intermediate Palomar Transient Factory (iPTF) collaboration: Upon receiving the final GBM localization for GRB 131231A, we selected ten fields to observe with the Palomar 48-inch Oschin telescope (P48) covering 62 deg^2, most of the 1-sigma GBM error circle. Due to the short remaining visibility window at Palomar, we obtained only one epoch of images of five of the ten fields covering 30 deg^2. This includes ~90% of the LAT error localization (Sonbas et al., GCN 15640). Sifting through 50 candidate variable sources near the LAT error circle using standard iPTF vetting procedures, at 1.45 hours after the burst we identify multiple uncatalogued sources, including iPTF13ekl at R=15.7 mag, at the coordinates RA(J2000) = 00h 42m 21.67s DEC(J2000) = -01d 39' 11.0" This position coincides with the Nanshan optical afterglow candidate at 7.91 hours after the burst (Xu et al., GCN 15641). There are no coincident sources in SDSS and no associated minor planets in the IAU Minor Planet Center database at this location. Despite the low ecliptic latitude of -5.7 deg, the two coincident optical detections separated by 6.46 hours strongly disfavor a solar system origin. These two observations fit a power-law decay with an index of alpha=-1.03, suggesting that the source is indeed associated with the GRB trigger. See for a depiction of the LAT error circle in relation to the P48 optical candidates, with iPTF13ekl highlighted, and a selection of the P48 fields observed.
GCN 15644 table
GRB_name GRB131231A
GCN_number 15644
Detection_method Fermi GBM Det
t_trigger 4:45:16.083 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 15644 SUBJECT: GRB 131231A: Fermi GBM detection DATE: 14/01/01 00:42:48 GMT FROM: Peter Jenke at MSFC P. Jenke (UAH) and S. Xiong (UAH) reports on behalf of the Fermi GBM Team: "At 04:45:16.083 UT on December 31 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131231A (trigger 410157919/131231198). This GRB was detected in a ground analysis by the Fermi LAT (Sonbas et al. GCN 15640). It was also detected in optical follow-up observations of the GBM position by DARK/NBI (Xu et al. GCN 15641) and iPTF (Singer et al. GCN 15643), and confirmed by NOT observations of the Fermi LAT position (Malesani et al. GCN 15642). The on-ground calculated location from GBM is consistent with the positions reported from these follow-up observations. The trigger resulted in an Autonomous Repoint Request (ARR) that was accepted and the LAT slewed to the GBM in-flight location. The initial angle from the LAT boresight is 38 deg from Fermi/GBM position. The GBM light curve consists of a single large peak preceded by a smaller peak which resulted in the trigger. The duration (T90) of the burst was about 31 s (50-300 keV). The time-averaged spectrum from T0+.003 s to T0+56 s is best fit with a Band function with Epeak = 146 +/- 3 keV, alpha = -1.10 +/- 0.01 and beta = -2.14 +/- 0.01. The event fluence (10-1000 keV) in this time interval is (2.51 +/- 0.01)E-06 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+22 s in the 10-1000 keV band is 67.3 +/- 0.8 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 15645 table
GRB_name GRB131231A
GCN_number 15645
Detection_method Optical
redshift 0.6420
Circular_text TITLE: GCN CIRCULAR NUMBER: 15645 SUBJECT: GRB 131231A: VLT/X-shooter redshift DATE: 14/01/01 02:36:10 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Xu (DARK/NBI), D. Malesani (DARK/NBI), N. R. Tanvir (Univ. Leicester), V. D'Elia (ASI/ASDC), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), T. Kruehler (ESO), J. P. U. Fynbo (DARK/NBI) report on behalf of a larger collaboration: We observed the optical counterpart of the Fermi/LAT GRB 131231A (Sonbas et al., GCN 15640; Jenke & Xiong, GCN 15644; Xu et al., GCN 15641) with the ESO VLT equipped with the X-shooter spectrograph. The mean time of our observation is 2014 Jan 1.04 UT, that is 20.2 hr after the GRB. The spectrum covers the wavelength range 3200 to 18,000 AA. The trace of the afterglow is well visible in all arms. We detect several absorption features which we interpret as due to Fe II, Mg II, Ca H and K, all at a common redshift z = 0.642 (wavelength solution based on archival calibration lamps). Emission lines corresponding to the [O III] doublet are also detected at the same redshift. We acknowledge excellent support from the observing staff in Paranal, in particular Steffen Mieske.
GCN 15646 table
GRB_name GRB131231A
GCN_number 15646
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15646 SUBJECT: GRB 131231A: MDM afterglow observation DATE: 14/01/01 08:13:16 GMT FROM: Jules Halpern at Columbia U. J. P. Halpern (Columbia U.) reports: I observed the afterglow of GRB 131231A (Sonbas et al., GCN 15640; Xu et al., GCN 15641) using the 1.3m McGraw-Hill telescope of the MDM Observatory on 2014 January 1, from 01:40 to 03:18 UT. Nineteen 5-minute exposures were obtained in the R-band. Conditions were photometric, and the Landolt standard-star field around PG0231+051 was used for calibration. The afterglow magnitudes measured for the first and last exposures of the sequence are: -------------------------------- Jan 1 UT t-t0(hr) R +/- -------------------------------- 01:40 20.92 18.48 0.02 03:18 22.55 18.61 0.02 -------------------------------- The following stars in field were calibrated, and can be used for comparison: ----------------------------------------- Star R.A.(2000) Decl.(2000) R ----------------------------------------- A 00 42 30.4 -01 36 13 16.07 B 00 42 11.7 -01 37 29 17.95 C 00 42 15.9 -01 39 08 17.92 D 00 42 20.0 -01 41 53 17.22 E 00 42 28.8 -01 40 16 17.96 -----------------------------------------
GCN 15647 table
GRB_name GRB131231A
GCN_number 15647
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15647 SUBJECT: GRB 131231A : xinglong TNT optical observation DATE: 14/01/01 13:10:54 GMT FROM: L.P. Xin at NAOC L. P. Xin, J. Y. Wei, X. F. Wang, Y. L. Qiu, J. S. Deng, J. Wang, X. H. Han and C. Wu on behalf of EAFON report: We began to observe GRB 131231A (Sonbas et al., GCN 15640; Xu et al., GCN 15641,15645; Malesani et al., GCN 15642; Singer et al. GCN 15643; Halpern GCN 15646) with Xinglong 0.8-m TNT telescope at 10:29:40 (UT) , Jan. 1th, at 2014, about 29.73 hours after the burst. 12*300 sec B,V,R-band images were obtained. The optical afterglow (Xu et al., GCN 15641) was clearly detected with a magnitude of 18.97+/-0.1 mag in R band, calibrated by USNO B1.0 R2mag at the mean time of 29.73 hours after the burst. Compared with the report by Halpern GCN 15646, the brightness of this afterglow decayed for 0.36 mag during the epoch between 22.55 hours and 29.73 hours after the burst. This message may be cited.
GCN 15648 table
GRB_name GRB131231A
GCN_number 15648
Detection_method Swift-XRT Other
ra 10.5904°
decl -1.6519°
redshift 0.6420
Circular_text TITLE: GCN CIRCULAR NUMBER: 15648 SUBJECT: GRB 131231A: Swift-XRT observations DATE: 14/01/01 17:39:26 GMT FROM: Vanessa Mangano at PSU V. Mangano (PSU), K. Page (U. Leicester), D. Malesani (DARK/NBI) report on behalf of the Swift-XRT team: We have analysed 4.0 ks of XRT data for the Fermi/LAT-detected burst: GRB 131231A, from 52.1 ks to 62.5 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is detected at a position consistent with the optical afterglow (Xu et al., GCN 15641) at a mean count rate of 0.4 ct/s. The refined XRT position is RA, Dec = 10.5904, -1.6519 which is equivalent to: RA (J2000): 00 42 21.70 Dec(J2000): -01 39 06.7 with an uncertainty of 3.5 arcsec (radius, 90% confidence). This position is 695 arcsec from the Fermi/LAT position and 4 arcsec from the optical afterglow. The light curve can be modelled with a power-law decay with an index of alpha=1.6 (+/-0.7). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.86 (+0.13, -0.13). The best-fitting absorption column at the redshift of 0.642 (Xu et al., GCN 15645) is 1.4 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 2.6 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.0 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. Further ToO observations have already been scheduled for today. This circular is an official product of the Swift-XRT team.
GCN 15650 table
GRB_name GRB131231A
GCN_number 15650
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15650 SUBJECT: GRB 131231A: P60 observations DATE: 14/01/02 05:09:18 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) reports on behalf of a larger collaboration: We imaged the location of GRB 131231A with the Palomar 60-inch (P60) robotic telescope on UT 2014-01-01 between 03:28:31 and 04:22:05, and again on 2014-01-02 between 01:56:28 and 02:37:12. Observations were taken in the g, r, i, and z filters during each epoch. The afterglow (Xu et al., GCN 15641) is well-detected in individual exposures in all bands. Both nights were photometric and we calibrated the field using an observation of the nearby standard field SA92. Some photometry of the GRB afterglow in the gri bands (all on the SDSS/AB system) is: r = 18.84 +/- 0.02 (t = 0.965 d) i = 18.72 +/- 0.02 (t = 0.970 d) g = 19.14 +/- 0.02 (t = 0.982 d) r = 19.77 +/- 0.03 (t = 1.886 d) i = 19.64 +/- 0.04 (t = 1.893 d) g = 20.06 +/- 0.03 (t = 1.907 d) The power-law temporal decay index in all bands is approximately alpha=1.3. We also give gri magnitudes of the five nearby calibration stars presented by Halpern (GCN 15646) for reference: star RA dec R g r i A 00:42:30.4 -01:36:13 16.07 16.86 16.28 16.11 B 00:42:11.7 -01:37:29 17.95 19.50 18.24 17.66 C 00:42:15.9 -01:39:08 17.92 19.16 18.20 17.85 D 00:42:20.0 -01:41:53 17.22 17.62 17.48 17.58 E 00:42:28.8 -01:40:16 17.96 18.76 18.18 18.02
GCN 15652 table
GRB_name GRB131231A
GCN_number 15652
Detection_method Other
redshift 0.6439
Circular_text TITLE: GCN CIRCULAR NUMBER: 15652 SUBJECT: GRB 131231A: Gemini-South Redshift DATE: 14/01/02 21:09:59 GMT FROM: Antonino Cucchiara at NASA/GSFC A. Cucchiara (ORAU/NASA-GSFC) reports on behalf of a larger collaboration: "On January 1.09 UT (~21.5 hours after the trigger) we observed the afterglow of GRB 131231A (Sombas et al. GCN 15640, Xu et al. GCN 15641, Malesani et al. 15642, Singer et al. GCN 15643) with the Gemini South telescope equipped with the GMOS camera. A series of spectroscopic observations in Nod & Shuffle more, was carried out using the R400 grating covering the 6000-10000 A wavelength range at an average airmass of 2.1. The resulting spectra show absorption features from CaH+K, as well as emission lines from forbidden [OII]3727 and [OIII]4959,5007 transitions at the common redshift of z=0.6439, consistent with the one reported by Xu et al. (GCN 15645). We thank the Gemini staff for performing these observations, in particular E. Marin and E. Wenderoth."
GCN 15670 table
GRB_name GRB131231A
GCN_number 15670
Detection_method Konus-Wind Det
t_trigger 4:45:32.361 UTC
redshift 0.6440
Circular_text TITLE: GCN CIRCULAR NUMBER: 15670 SUBJECT: Konus-Wind observation of GRB 131231A DATE: 14/01/03 17:15:47 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 131231A (Fermi-LAT detection: Sonbas, et al., GCN 15640; Fermi-GBM observation: Jenke & Xiong, GCN 15644) triggered Konus-Wind at T0=17132.361 s UT (04:45:32.361). The light curve shows a broad mult-peaked pulse from ~T0-13 s to ~T0+35 s. The emission is seen up to ~15 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131231_T17132/ Note: periodic 'dips' in the count rate are due to the GRB source occultation by the s/c structure. As observed by Konus-Wind, the burst had a fluence of (1.55 0.05)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+7.488 s, of (2.14 0.13)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+34.303 s) is best fit in the 35 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.28 0.04, the high energy photon index beta = -2.47 0.05, the peak energy Ep = 163 6 keV, chi2 = 93.8/95 dof. The spectrum near the maximum count rate (measured from T0+5.888 s to T0+8.448 s) is best fit in the 35 keV - 10 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -0.76 0.09, and the peak energy Ep = 226 14 keV, chi2 = 94.3/82 dof. Assuming the redshift z=0.644 (Xu, et al., GCN 15645; Cucchiara, GCN 15652), 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 (1.7 0.1)x10^53 erg, the peak luminosity L_iso is (3.9 0.2)x10^52 erg/s, and the rest-frame peak energy Ep,i = (270 10) keV All the quoted results are preliminary.
GCN 15672 table
GRB_name GRB131231A
GCN_number 15672
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 15672 SUBJECT: GRB 131231A: Fermi GBM correction to GCN 15644 DATE: 14/01/03 19:03:04 GMT FROM: Peter Jenke at MSFC P. Jenke (UAH) reports on behalf of the Fermi GBM team: "The quoted fluence (10-1000 keV) in GCN 15644 (P. Jenke et al) was in fact the time integrated average energy flux for this burst. The actual fluence (10-1000 kev) for this event is (1.400 +/- 0.001)E-4 ergs/cm^2."
GCN 15673 table
GRB_name GRB131231A
GCN_number 15673
Detection_method Swift-UVOT Det
ra 10.5902°
decl -1.6529°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15673 SUBJECT: GRB 131231A: Swift/UVOT Observations of the Optical Afterglow DATE: 14/01/03 19:47:04 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) and V. Mangano (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began observations of the field of GRB 131231A 136.5 ks after the Fermi/LAT trigger (Sonbas et al., 2013, GCNC 15640). The preliminary UVOT position is RA (J2000) 00:42:21.66 = 10.59025 (deg) Dec (J2000) -01:39:10.6 = -1.65294 (deg) with an estimated uncertainty of 0.43 arcsec (radius, 90% confidence, statistical + systematic). We detect the optical afterglow at the position reported by Xu et al. (2013, GCNC 15641). Preliminary UVOT photometry is presented below. ------------------------------------------------------ Filter TSTART TSTOP Exposure Mag Err ------------------------------------------------------ u 246,875 248,554 1652 19.57 0.10 white 136,762 138,942 1650 19.37 0.05 white 228,985 231,172 1639 20.07 0.07 ------------------------------------------------------ The quoted magnitudes and upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.02 mag (Schlafly et al. 2011, ApJS, 737, 103). The photometry is in the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373). The white observations yield a power-law decay index of alpha ~ 1.25 between 1.6 and 2.7 days. This is consistent with that found by Perley et al. (2014, GCNC 15650) between 1.0 and 1.9 days. The power-law decay index in the X-ray band at this time is alpha ~ 1.6 (Mangano et al. 2014, 15648), suggesting that there may be a cooling break between the optical and X-ray regimes.
GCN 15676 table
GRB_name GRB131231A
GCN_number 15676
Detection_method Fermi LAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 15676 SUBJECT: GRB 131231A, Optical Observations DATE: 14/01/04 12:00:42 GMT FROM: Shashi Bhushan Pandey at ROTSE S.B. Pandey, Brajesh Kumar and Archana Soam (ARIES Nainital India, on behalf of larger Indian GRB collaboration) The Fermi-LAT detected GRB 131231A (Sonbas et al., GCN 15640; Xu et al., GCN 15641) was monitored with the 1.04m and 1.3m telescopes at ARIES Nainital starting at 2014-01-01 13:15:13 (UT). Several images in R_c and I_c pass-bands were obtained. The optical afterglow was clearly detected in individual frames. The preliminary photometry of the first R_c frame (exposure time 300 sec) yields afterglow magnitude to be 19.2+-0.1 mag. The nearby USNO stars have been used for calibrate. This massage may be cited.
GCN 15680 table
GRB_name GRB131231A
GCN_number 15680
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15680 SUBJECT: GRB 131231A: CARMA 3mm detection DATE: 14/01/05 01:15:53 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) reports on behalf of a larger collaboration: We observed the position of GRB 131231A (Sonbas et al., GCN 15640; Jenke and Xiong, GCN 15644) with the Combined Array for Research in Millimeter Astronomy between 2013-01-01 23:54:54 UT and 2013-01-02 02:02:17 UT (1.798-1.887 days post-GRB) at a mean frequency of ~93 GHz, under good conditions. We identify a weak source consistent with the optical localization (Xu et al., GCN 15651; Singer et al., GCN 15643) in the reduced map. The afterglow flux at this time is measured to be 0.85 +/- 0.25 mJy. We thank observers B. A. Zauderer and M. Balokovic and the CARMA staff for executing the observation.
GCN 15681 table
GRB_name GRB131231A
GCN_number 15681
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15681 SUBJECT: GRB 131231A : Lulin Optical Observations DATE: 14/01/05 01:36:03 GMT FROM: Yuji Urata at Nat. Central U. K.Y. Huang (NTNU), Y. Urata (NCU) on behalf of EAFON report: We observed the optical afterglow of GRB131231A (Xu et al., GCN 15641) using the Lulin One-meter Telescope (LOT) with g, r, i, and z filters. The monitoring observation was made on the night of 1, 2 and 4, Jan, 2014. Based on nearby stars reported by Halpern (GCN15646) and Perley (GCN15650), we made photometry of the GRB afterglow. The temporal decay index alpha remains ~1 including the latest epoch. Some of photometry is summarized below. epoch(d) g-mag g-err 1.259 19.6 0.1 2.247 20.3 0.1 4.377 20.9 0.1
GCN 15711 table
GRB_name GRB131231A
GCN_number 15711
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15711 SUBJECT: GRB 131231A: AAO optical observations DATE: 14/01/09 16:06:01 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V. Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical counterpart of the Fermi/LAT GRB 131231A (Sonbas et al., GCN 15640; Xu et al. GCN 15641) with AS-32 (0.7m) telescope of Abastumani Observatory on Jan. 3, 4, and 5. We obtained several unfiltered images of 120 s exposure during each observational set. On stacked images we clearly detect the afterglow. The photometry based on the reference stars, R-mag, from Halpern (GCN 15646) is following: Date T_start t-t0, exp, OT (UT) mid, d s 2014-01-03 17:08:16 3.54893 33x120 20.26 ± 0.06 2014-01-04 16:53:04 4.53207 29x120 20.32 ± 0.08 2014-01-05 15:59:46 5.50061 34x120 20.74 ± 0.13