//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15971 SUBJECT: Fermi416242156: possible iPTF counterpart DATE: 14/03/12 18:50:02 GMT FROM: Leo Singer at CIT/PTF L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal (Carnegie Observatories/Princeton) report on behalf of the intermediate Palomar Transient Factory (iPTF) collaboration: We have searched for optical counterparts of Fermi GBM trigger 416242156 (2014-03-11 14:49:13.10) using the Palomar 48-inch Oschin telescope (P48). We observed 10 fields, covering 73.0 deg2 and most of the Fermi GBM 1-sigma contour. We estimate a 54% chance that our fields contain the location of the source. Sifting through candidate variable sources using image subtraction and standard iPTF vetting procedures including photometry with the robotic Palomar 60" telescope (P60), we detect the candidate optical transient iPTF14aak, the coordinates: RA(J2000) = 11h 33m 14.47s (173.310295 deg) Dec(J2000) = +62d 05' 10.7" (+62.086313 deg) In our P48 image taken dt=0.51 days after the Fermi trigger, we measure r = 19.7 +/- 0.1 mag. In our P60 image taken dt=0.82 days after the trigger, we find a limit of r > 20.10 mag. Given a bright star about 1.3' to the west, it is possible that the P48 detection is a ghost. If not, then the P60 non-detection is evidence of fading with a power law of at least alpha~0.8. We have submitted a Swift target of opportunity to search for an X-ray counterpart of iPTF14aak. Further observations are encouraged to confirm the nature of the source, and determine if it is associated with the Fermi trigger. The diagram http://www.its.caltech.edu/~lsinger/iptf/Fermi416242156.pdf shows the ten P48 fields and the position of iPTF14aak in relation to the Fermi GBM 1- and 2-sigma statistical+systematic contours. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15977 SUBJECT: GRB 140311C: Fermi GBM Detection DATE: 14/03/12 22:28:45 GMT FROM: Matthew Stanbro at UAH/Fermi M. Stanbro (UAH) reports on behalf of the Fermi GBM Team: "At 14:49:13.10 UT on 11 March 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140311C (trigger 416242156/140311618). iPTF reported an optical counterpart candidate for this source (L.P. Singer et al. 2014, GCN 15971). The GBM on-ground location, using the Fermi GBM trigger data, is RA = 183.7 , DEC = +62.81 (J2000 degrees, equivalent to 12h 14m, 62d 48'), with an uncertainty of 3 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle to the Fermi LAT boresight is 53 deg. The GBM light curve consists of single peak with a duration (T90) of 14 s (50-300 keV). The time-averaged spectrum from T0-2 s to T0+12 s is well fit by a Band function parameterized as Epeak = 56 +/- 6 keV, alpha = -0.9 +/- 0.16 and beta = -2.4 +/- 0.12. The event fluence (10-1000 keV) in this time interval is (4.6 +/- 0.2)E-06 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+0.3 s in the 10-1000 keV band is 10.7 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15981 SUBJECT: GRB 140311C: MASTER before, during and after trigger optical observations DATE: 14/03/13 15:55:07 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, M. Pruzhinskaya, D.Denisenko, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, 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 Blagoveschensk was pointed to the GRB140311C (M. Stanbro, GCN15977) 14 sec after notice time and 29 sec after trigger time at 2014-03-11 14:49:42.721 UT . On our first (10s exposure) set we haven`t found optical transient within FERMI error-box (ra=12 47 02 dec=+58 49 46 FOV=2x4 square degrees). The 5-sigma upper limit has been about 16.3 mag MASTER II robotic telescope located in Tunka was pointed to the GRB140311C (M. Stanbro,GCN15977) 35 sec after trigger time at 2014-03-11 14:49:48.874 UT. On our first (10s exposure) set we haven`t found optical transient within FERMI error-box (ra=12 47 02 dec=+58 49 46 FOV=2x4 square degrees). The 5-sigma upper limit has been about 16.0 mag. We have done survey of the large area around initial error box up to ~18 unfiletred magnitude which was begun in 15 minutes after GRB. The GBM error box (M. Stanbro, GCN15977) completely observed by 4-th Very Wide Field Cameras (FOV = 4x380 square degrees) before, during and after GRB without time gap up to 11 unfiltered magnitude limit on each 5 sec image. The reduction is continued now. The IPN is very desirable. The covarege map is available at http://master.sai.msu.ru/static/GRB/GRB140311C_map.png . The elliptical region is the Fermi GBM 1 sigma+3 degrees systematic error box. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15982 SUBJECT: GRB 140311C: Swift-XRT and UVOT observations DATE: 14/03/13 18:05:25 GMT FROM: Valerio D'Elia at ASDC V. D'Elia (ASDC), L.M.Z. Hagen (PSU), L. Izzo (URoma/ICRA), P. D'Avanzo (INAF-OAB), S. Holland (STScI) report on behalf of the Swift team: We report on Swift observations of the field of the GBM discovered GRB140311C burst (Stanbro, GCN Circ 15977), for which a possible optical counterpart was reported by iPTF (Singer et al., GCN Circ 15971). XRT began observing the field on 2014-03-12 at 23:43:48 UT, i.e.,  118 ks after the trigger, for a total of 2.7ks. No source is detected at the iPTF coordinates, nor in the whole XRT field of view. The 3-sigma upper limit on the count rate is 5E-03 cts/s. The Swift/UVOT began settled observations of the field of GRB 140311C 118480 s after the trigger. No optical afterglow consistent with the iPTF position (Singer et al., GCN Circ. 15971) is detected in the initial UVOT exposure. The preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter         T_start(s)   T_stop(s)      Exp(s)         Mag u               118480       125414         2916        >21.43 The magnitude in the table is not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).  We note that the photometry may be affected by a nearby bright foreground star. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15983 SUBJECT: GRB 140311C: MASTER optical observations DATE: 14/03/14 15:01:38 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, M. Pruzhinskaya, D.Denisenko, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, 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) As previously reported (Yurkov et. al. GCN 15981) MASTER VWF robotic very wide field cameras (FOV=2x384 square degrees, D=72mm, f/1.2, 1 pix = 22 arcsec) installed on MASTER-II robotic telescope in Tunka covered full FERMI GBM error-box (M. Stanbro, GCN15977) before, during and after GRB. We haven`t found credible optical transient with 3-sigma upper limit 10.5m. We also didn't find credible optical counterpart on the survey (Yurkov et. al. GCN 15981) of part of error box carried out directly after GRB on MASTER-II robotic telescope up to 18 mag. The synchronous move of FERMI GBM error-box available here http://master.sai.msu.ru/static/GRB/GRB140311C_FERMI.gif http://master.sai.msu.ru/static/GRB/GRB140311C_diff.gif The circle on move is the Fermi GBM 1 sigma+3 degrees systematic error box. Also very wide field cameras covered a place of possible iPTF counterpart (Singer et. al. GCN 15971). Unfortunately the bright star is projected into OT place. We didn't find a noticeable brightening of this star. The syncronous move from very wide field cameras of possible iPTF counterpart place available here http://master.sai.msu.ru/static/GRB/GRB140311C_IPTF.gif This place was not covered on MASTER-II survey. The Prompt Optical to Gamma Fluence Ratio during this burst is: F_opt/F_gamma <~ 1 : 820. The covarege map is available at http://master.sai.msu.ru/static/GRB/GRB140311C_map1.png . The message may be cited.