//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6856 SUBJECT: GRB 071008: Swift detection of a burst DATE: 07/10/08 22:04:30 GMT FROM: Scott Barthelmy at NASA/GSFC A. Moretti (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC), V. Mangano (INAF-IASFPA), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 21:55:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071008 (trigger=293587). The BAT on-board calculated location is RA, Dec 151.548, +44.334 which is RA(J2000) = 10h 06m 11s Dec(J2000) = +44d 20' 02" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 15 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. Because Swift is in the process of returning to normal operations, automatic slewing to GRBs is currently disabled outside of business hours (US EDT). Therefore, there are no prompt XRT or UVOT observations of this burst. Burst Advocate for this burst is A. Moretti (moretti AT merate.mi.astro.it). 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.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6857 SUBJECT: GRB071008: IAC80 observation DATE: 07/10/09 17:15:01 GMT FROM: Martin Jelinek at Inst.Astrophys.Andalucia,Granada Martin Jelinek, Alberto J. Castro-Tirado, Javier Gorosabel (IAA-CSIC Granada) and R. Piontek (AIP Potsdam) report on behalf of larger collaboration: We observed the Swift-BAT errorbox of a GRB 071008 (trigger=293587, Moretti et al., GCN 6856), with an IAC 80cm telescope at La Palma starting at 05:43 UT (7.8h after the GRB). Our 3 x 180s combined R-band image has a limiting magnitude of R < 21.5 and does not show any new source in comparison to a DSS-Red, implying a DSS-equivalent limit to the afterglow detection. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6866 SUBJECT: GRB071008: Swift-XRT observation DATE: 07/10/10 10:37:43 GMT FROM: Alberto Moretti at Obs Brera Merate A. Moretti (INAF-OAB), C. Guidorzi (Univ. Bicocca & INAF-OAB), P. Romano (Univ. Bicocca & INAF-OAB), report on behalf of the Swift-XRT team: Swift XRT observed the GRB 071008 (trigger=293587, Moretti et al., GCN Circ. 6856) beginning 57 ks after the BAT trigger. In 6857s of Photon Counting mode data spanning 57-65 ks after the trigger in the BAT error circle we found 2 faint sources at RA,Dec =151.58851,44.32071 and RA,Dec =151.55340, 44.34459 which are RA(J2000) = 10 06 21.24 Dec(J2000)= +44 19 14.5 RA(J2000) = 10 06 12.82 Dec(J2000)= +44 20 40.5 with error circles of radius 6.5 and 7.5 arcseconds (90%, including boresight uncertainties) respectively. They are at 116 and 40 arcseconds from the BAT position, respectively. At present, due to the paucity of the observed events, we are unable to determine whether these sources are fading. Further observations will be planned when the distance to the Sun will be larger. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6869 SUBJECT: GRB 071008, Swift-BAT refined analysis DATE: 07/10/10 15:47:08 GMT FROM: Scott Barthelmy at NASA/GSFC E. Fenimore (LANL), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), A. Moretti (INAF-OAB), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 071008 (trigger #293587) (Moretti, et al., GCN Circ. 6856). The BAT ground-calculated position is RA, Dec = 151.571, 44.303 deg which is RA(J2000) = 10h 6m 17.0s Dec(J2000) = 44d 18' 13" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 88%. The mask-weighted light curve shows a symmetrical peak starting at ~T-11 sec, peaking at ~ T-1 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 18 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-11.0 to T+14.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.23 +- 0.27. The fluence in the 15-150 keV band is 2.4 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-2.04 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6874 SUBJECT: GRB071008: optical observations DATE: 07/10/11 00:43:38 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 error box of short GRB071008 (Moretti et al., GCN 6856) with Shajn 2.6m telescope of CrAO on Oct. 9. Series of images were obtained between (UT) 00:15:12 and 01:30:43 in R filter. The limiting magnitude (3 sigma) of a combined image calibrated against USNO-A2.0 is 24.3 mag. The combined image of a total exposure of 4020 s (67x60 s) covers entire of the refined BAT error box (Fenimore et al., GCN 6869). Within error circles of the two XRT sources (Moretti et al., GCN 6866) we found following optical objects. Within XRT source at RA(J2000) = 10 06 21.24 Dec(J2000)= +44 19 14.5 there is a galaxy S1 which also can be detected in SDSS images. However the galaxy S1 is out of the refined BAT error box (Fenimore et al., GCN 6869). Within XRT source at RA(J2000) = 10 06 12.82 Dec(J2000)= +44 20 40.5 we marginally detect S2 object. It is necessary a second epoch observation to decide about nature of the S2 object. The combined image can be found at http://grb.rssi.ru/GRB071008. The message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7113 SUBJECT: Swift XRT follow-up observations of GRB071008 DATE: 07/11/19 14:50:58 GMT FROM: Alberto Moretti at Obs Brera Merate A. Moretti (INAF-OAB), C. Guidorzi (Univ. Bicocca & INAF-OAB), report P. Romano (Univ. Bicocca & INAF-OAB) on behalf of the Swift XRT team: The Swift XRT re-observed the field of GRB 071008 (trigger=293587, Moretti et al., GCN Circ. 6856) on 2007 November 15-19 for a total exposure of 10.7 ks. The first source listed in GCN Circ 6866 (Moretti et al., 2007), which is the only one in the refined BAT error circle (GCN Circ. 6869 Fenimore et al. 2007) is no more detectable. The chance probability of no variation between the two epochs is < 1E-4. We conclude that this source is the X-ray afterglow of GRB 071008 and its position is RA(2000)=151.58851, Dec(2000)=44.3207 which corresponds to RA(2000) = 10h06m21.24s Dec(2000) = +44 19 14.6 with a 5.8" radius error circle (90% confidence). The 3-sigma upper count rate limit at the position of the burst at 3.1E6 seconds after the trigger is 7e-4 counts/s which converts roughly to 4e-14 ergs/s/cm2. This circular is an official product of the Swift team