//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19251 SUBJECT: GRB 160401A: a long GRB detected by INTEGRAL DATE: 16/04/01 21:32:32 GMT FROM: Sandro Mereghetti at IASF/CNR S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma ray burst lasting about 130 s has been detected by IBAS in the IBIS/ISGRI data at 20:20:30 UT of April 1, 2016. The refined coordinates (J2000) are: R.A.= 89.7377 deg DEC.= 26.6758 deg with an uncertainty of 2 arcmin (90% c.l.). The burst had a peak flux of 0.7 counts/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 1e-6 erg/cmq. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19252 SUBJECT: GRB 160401A: MASTER-IAC prompt optical observations DATE: 16/04/01 22:07:26 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs R. Rebolo, M. Serra Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias V. Lipunov, E.Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory 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-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Teyde observatory was pointed to the GRB160401.85 (Mereghetti et al., GCN 19251) 7 sec after notice time and 15 sec after trigger time at 2016-04-01 20:20:57 UT. On our first (10s exposure) set we didn't find new optical transient within INTEGRAL error-box (ra=05 59 00 dec=+26 41 11 r=0.054) brighter then 16.3 (5-sigma upper limit). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19253 SUBJECT: GRB 160401A: Swift ToO observations DATE: 16/04/02 08:18:21 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the INTEGRAL GRB 160401A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020603 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the INTEGRAL event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19254 SUBJECT: GRB 160401A: LT observations DATE: 16/04/02 14:04:12 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), A. Gomboc (U. Nova Gorica), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), on behalf of a large collaboration report: The 2-m Liverpool Telescope automatically began observing INTEGRAL GRB 160401A (Mereghetti et al. GCN 19251) on April 01, 20:23:44 UT, i.e. 3.2 minutes since the GRB trigger time. From the subtraction of two 3x10-s r-band frames taken at 46 and 68 minutes post GRB trigger we do not detect any uncatalogued, significantly variable object within the INTEGRAL error circle down to r~20 mag calibrated against nearby USNOB-1 stars, in agreement with previous reports (Rebolo et al. GCN 19252). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19255 SUBJECT: GRB 160401A: Zadko observatory - Gingin optical observations DATE: 16/04/02 14:19:27 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.), Coward, D. McPherson, D. Williams A., Martin R., Moore J., Dodson R. (UWA) report: We imaged the field of GRB 160401A detected by Integral (Mereghetti et al. GCNC 19251) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 0.63 day after the GRB trigger as soon as the night became. The elevation of the field decreased from 27 degrees above horizon and weather conditions were good. We co-added a series of exposures. We did not observed any new optical source than those in the SDSS in a radius of 2 arcmin centered ont the position RA=05:58:57 Dec=+26:40:33 J2000.0: t1(d) t2(d) Rmag_lim 0.63 0.66 19.0 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=183.4 lat= +1.4 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19256 SUBJECT: GRB 160401A: Swift/UVOT Upper Limits DATE: 16/04/02 20:08:19 GMT FROM: Paul Kuin at MSSL Paul Kuin (MSSL/UCL) and L.M. McCauley (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160401A 43ks s after the INTEGRAL trigger (Mereghetti et al., GCN Circ.19251). No optical afterglow consistent with the INTEGRAL position is detected in the initial UVOT exposures. The burst location was also observed by MASTER-IAC (Rebolo et al., GCN Circ. no. 19252); LT (Guidorzi et al. GCN Circ. no. 19254), and the Zadko observatory (Klotz et al. GCN Circ. 19255); none of whom observed an afterglow. Preliminary 3-sigma upper limits 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 white 43678 44209 522 >20.8 v 44509 45370 843 >19.5 u 42847 43671 811 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.13 in the direction of the burst (Schlegel et al. 1998). [GCN OPS NOTE(02apr16): The letter 'A' was added to the GRB name.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19257 SUBJECT: GRB 160401A: Swift-XRT observations DATE: 16/04/03 15:29:59 GMT FROM: Marissa McCaule at PSU L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the INTEGRAL-detected burst GRB 160401A (Mereghetti et al. GCN Circ. 19251), collecting 2.9 ks of Photon Counting (PC) mode data between T0+42.9 ks and T0+49.1 ks. No X-ray sources have been detected inside or close to the INTEGRAL error region. The 3-sigma upper limit in the field ranges from ~0.003 to ~0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.3e-13 to 1.9e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Four uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020603. This circular is an official product of the Swift-XRT team.