//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15546 SUBJECT: IPN Triangulation of GRB 131125A (short/hard) DATE: 13/11/29 13:08:03 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and K. Hurley on behalf of the IPN team, report: The short-duration, hard spectrum GRB 131125A has been observed by Fermi (GBM: trigger 407089974), INTEGRAL (SPI-ACS), and Konus-Wind, so far, at about 59571 s UT (16:32:51). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 114.675 (07h 38m 42s) +48.414 (+48d 24' 49") Corners: 114.485 (07h 37m 56s) +45.684 (+45d 41' 01") 115.166 (07h 40m 40s) +45.939 (+45d 56' 21") 114.817 (07h 39m 16s) +51.137 (+51d 08' 15") 114.077 (07h 36m 18s) +50.873 (+50d 52' 22") --------------------------------------------- The error box area is 2.5 sq. deg, and its maximum dimension is 5.5 deg (the minimum one is 29 arcmin). The Sun distance was 130 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB131125_T59571/IPN/ The time history and spectrum will be given in forthcoming GCN Circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15549 SUBJECT: Konus-Wind observation of GRB 131125A DATE: 13/11/29 15:52:50 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 short-duration, hard-spectrum GRB 131125A (IPN Triangulation: Golenetskii et al. GCN 15546) triggered Konus-Wind at T0=59572.927 s UT (16:32:52.927). The burst duration is ~0.5 s. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131125_T59572/ As observed by Konus-Wind, the burst had a fluence of (1.3 ± 0.2)x10-6 erg/cm2, and a 64-ms peak flux, measured from T0-0.064, of (5.7 ± 1.2)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The 3-channel time-integrated spectrum (measured from T0-0.448 to T0+0.064 s) can be modeled, in the 22 keV - 1.3 MeV range, by the cutoff power law with the following model parameters: the photon index alpha = 0.00 ± 0.13, and the peak energy Ep = 638 ± 62 keV. The 3-channel spectrum at the maximum count rate (measured from T0-0.064 s to T0) can be modeled, in the 22 keV - 1.3 MeV range, by the cutoff power law with the following model parameters: the photon index alpha = +0.2 ± 0.3, and the peak energy Ep = 665 ± 113 keV. All the quoted results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15552 SUBJECT: GRB 131125A: iPTF upper limits on the afterglow of a short GRB DATE: 13/11/29 17:47:17 GMT FROM: Leo Singer at CIT/PTF L. P. Singer (Caltech), M. M. Kasliwal (Carnegie Observatories), and S. B. Cenko (NASA/GSFC) report on behalf of the intermediate Palomar Transient Factory (iPTF) collaboration: The short-hard GRB 131125A triggered Fermi GBM (Fermi trigger 407089974) at 2013-11-25 16:32:47 and was localized by IPN using Fermi, INTEGRAL, and Konus-Wind (Golenetskii et al., GCN 15546). Starting 2013-11-26 04:16 UT, we imaged about 95 deg^2 surrounding the Fermi GBM localization, covering most of the intersection between the GBM 1-sigma statistical+systematic error contour and the IPN Fermi-INTEGRAL 3-sigma annulus, also including the entire intersection with the Fermi-Wind annulus. Using standard iPTF vetting procedures including Palomar 60-inch follow-up, we find no afterglow candidates to an average limiting magnitude of R~20.4 at 11.8 hours after the burst. See http://www.its.caltech.edu/~lsinger/iptf/Fermi407089974.pdf for a diagram of the PTF fields observed in relation to the Fermi and IPN localizations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15553 SUBJECT: GRB 131125A: MASTER-Net very early optical observations DATE: 13/11/29 18:47:14 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs Gorbovskoy, V. Lipunov,D.Denisenko, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, Sternberg Astronomical Institute, Moscow State University K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB131125A 10 s after notice time and 24 sec after GRB time at 2013-11-25 16:33:25 UT. But IPN error box (GCN 15546) was outside of FOV of our MASTER-II telescope and very wide field camera (usually we follow up all Fermi alerts). After first coordinates specification we cover IPN error box using very wide field cameras. The first images covered error-box was obtained 49 sec after GRB time at 2013-11-25 16:33:40 UT. The 5-sigma upper limit has been about 12 mag on single 5 seconds exposure images and 13.5 on coadd of first 14 consecutive images The 5-sigma upper limit has been about 14.1 mag We find several optical marginal candidates to OT. Name R.A. Dec. m MASTER_1 114.775649 46.120371 13.6 MASTER_2 114.597740 48.927898 13.7 MASTER_3 114.835195 47.047021 13.0 One sigma coordinate error is +- 7 arcsec. The first image available here: http://master.sai.msu.ru/static/GRB/GRB131125_first.jpeg The coadd images here: http://master.sai.msu.ru/static/GRB/GRB131125_coadd.jpeg The message may be cited.