//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6907 SUBJECT: GRB 071013: Swift detection of a burst DATE: 07/10/13 12:49:52 GMT FROM: Scott Barthelmy at NASA/GSFC F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), G. Cusumano (INAF-IASFPA), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (Univ. Bicocca & INAF-OAB), G. Sato (GSFC/ISAS), B. Sbarufatti (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 12:09:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071013 (trigger=294120). Swift did not execute an immediate slew. The BAT on-board calculated location is RA, Dec 279.525, +33.857 which is RA(J2000) = 18h 38m 06s Dec(J2000) = +33d 51' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a peak ~40 sec duration. The peak count rate was ~800 counts/sec (15-350 keV), at ~2 sec after the trigger. There are no XRT or UVOT data products because auto-slewing to new bursts is disabled while in gyro-calibration mode. Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 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: 6910 SUBJECT: GRB071013: optical limit DATE: 07/10/13 16:47:58 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Klunko(ISTP), A. Marchenkov (ISTP), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the error box of GRB071013 (Marshall et al., GCN 6907) in R-band on Oct.13 with 1.5m telescope of Sayan observatory. A set of images of 120 s exposure was obtained starting (UT) 13:20:27. No obvious optical candidate is found within BAT error circle in the first image (UT) 13:20:27 in comparison with DSS2. Based on USNO A2.0 we estimate limiting magnitude of the first image as R=19.2. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6911 SUBJECT: GRB 071013, Swift-BAT refined analysis DATE: 07/10/13 17:24:19 GMT FROM: Scott Barthelmy at NASA/GSFC D. Palmer (LANL), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), 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-119 to T+183 sec from recent telemetry downlinks, we report further analysis of BAT GRB 071013 (trigger #294120) (Marshall, et al., GCN Circ. 6907). The BAT ground-calculated position is RA, Dec = 279.501, 33.846 deg which is RA(J2000) = 18h 38m 0.3s Dec(J2000) = 33d 50' 46" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%. The mask-weighted light curve shows a single peak starting at ~T-5 sec, peaking at ~T+5sec, and ending at ~T+30 sec. T90 (15-350 keV) is 26 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-5.9 to T+23.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.60 +- 0.36. The fluence in the 15-150 keV band is 3.2 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+3.69 sec in the 15-150 keV band is 0.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6908 SUBJECT: GRB 20071013: Xinglong TNT optical Upper Limit DATE: 07/10/13 14:11:24 GMT FROM: L.P. Xin at NAOC L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J.Wang and W.K. Zheng on behalf of EAFON report: We have imaged the field of GRB 071013(Marshall et al., GCN 6907) with the TNT 0.8m telescope at Xinglong Observatory started from 12:14:08 UT , 289s after the burst. A series of White and R band images were obtained, no new source was found in our combined images within the error region of the BAT. The 3-sigma limit derived form USNO-B1.0 R mag is ------------------------------------ Band Mid time Exp time Limit Mag White 504s 19*20s 20.0 R 1538s 20*60s 20.2 Further observation is under going. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6912 SUBJECT: GRB 071013: optical observations at NOT DATE: 07/10/13 23:30:48 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center D. Malesani, (DARK), J. Gorosabel (IAA-CSIC), P. Jakobsson (Univ. Hertfordshire), J.P.U. Fynbo (DARK), J. Niemela, C. Villforth (NOT) report on behalf of larger collaboration: We observed the field of GRB 071013 (Marshall et al., GCN 6907) using the Nordic Optical Telescope. Observations were carried out in the R and I filters, with mean integration epochs on Oct 13.867 and 13.894 UT (8.65 and 9.30 hr after the GRB). By comparison with the DSS, we do not detect any obvious candidate afterglow down to the DSS limiting magnitude R~20.5. Further observations are planned. [GCN OPS NOTE(14oct07): Per author's request, the Fynbo affiliation was changed from "NOT" to "DARK".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6913 SUBJECT: GRB 071013: Optical observations DATE: 07/10/14 13:54:35 GMT FROM: Kuntal Mishra at ARIES,Nainital,India Rupak Roy, K. Misra and S. B. Pandey (ARIES, NainiTal, India, on behalf of larger Indian GRB collaboration) We imaged the field of Swift GRB 071013 (Marshall, F. E. et al. GCN6907) with the 1.04m telescope at NainiTal ~ 5 hours after the burst. Observations were performed in R and I bands in poor sky conditions. No afterglow candidate was found in our combined images within the error region of BAT. The 3-sigma limit derived form USNO-B1.0 is I ~20 mag. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6917 SUBJECT: GRB 071013: TLS Upper Limit DATE: 07/10/15 20:08:41 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report: We observed the field of GRB 071013 (Marshall et al., GCN 6907) with the Tautenburg 1.34m Schmidt telescope under good conditions, obtaining 13 600 second images in the Rc band. Within the revised BAT error circle (Palmer et al., GCN 6911), we find no new sources in comparison to the DSS. We note that our stacked image is much deeper than the DSS, and contains many additional faint sources. More precise analysis awaits the publication of a Swift XRT position. Assuming the USNO B1.0 star at RA (J2000) = 18:38:05.67, Dec. (J2000) = +33:54:14.61 to have R2=17.22, we derive the following magnitude limit for regions not close to bright stars: Date Mid-Time Rc limit (2 sigma) 13.79254 0.28608 23.0 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6925 SUBJECT: GRB071013: optical observations DATE: 07/10/16 18:57:43 GMT FROM: Alexei Pozanenko at IKI, Moscow G. Kornienko, A. Erofeeva (UAFO), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the error box of GRB071013 (Marshall et al., GCN 6907) on Oct.13 with SR-22 telescope of UAFO observatory. A set of 50 unfiltered images of 60 s exposure was obtained starting (UT) 12:33:04. In images between 12:39:04 - 12:49:04 we observed an object at the position RA(J2000) = 18:37:49.1 Dec(J2000)= +33:50:25 with uncertainties of 3" in both coordinates. The object is not visible before and after this time (UT)12:39:04 - 12:49:04. The object is in refined BAT error circle (Palmer et al., GCN 6911). Based on nearby USNO-A2.0 stars we estimate brightness of the object as R~18.2. The source of USNO-B1.0 1238-0299614 (RA(J2000)=18 37 48.84 Dec(J2000)= +33 50 26.7) sits close (or coincides) to our object and it has R2=19.6. The photometry of the source in deep TLS observation (Kann et al., GCN 6917) is R=19.5 (Kann, private communication). If the USNO-B1.0 1238-0299614 source is a galaxy, then the afterglow may be masked of the galaxy in later times. At this time we cannot confirm the nature of the found object and we encourage to refine observations at the same period (Xin et al., GCN 6908). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6929 SUBJECT: GRB 071013: TNT optical data refined analysis DATE: 07/10/17 15:08:04 GMT FROM: L.P. Xin at NAOC L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J.Wang and W.K. Zheng on behalf of EAFON report: We refined the TNT data obtained in Oct. 13 (GCN 6908) the object observed by Kornienko et al. (GCN 6925) can not be confirmedin our R band images that were observed in the same period.Our data was taken under bad seeing ~4". In combined 6*60s R band image taken bewteen 12:39:03 - 12:47:54 (UT), we could not see the object at the position RA(J2000)=18:37:49.1 Dec(J2000)=+33:50:25(Kornienko et al., GCN 6925). The source of USNO-B1.0 1238-0299614(RA(J2000)=18:37:48.84 Dec(J2000)= +33:50:26.7) was marginally detected in this combined image at 2.5 sigma level, and no obvious new object around was detected at the same sigma level. We examined images before and after this period, also no obvious new object was detected. Using the same comparison star at RA (J2000) = 18:38:05.67, Dec (J2000) = +33:54:14.61 which has R2=17.22 (Kann et al., GCN 6917, GCN 6926),we estimate the USNO-B1.0 1238-0299614 star had the following magnitude at the epoch of our observation (GCN 6908): --------------------------------------------------- T_start(UT) T_stop(UT) Band Exptime Mag M_err 12:21:38 12:38:45 R 13*60s 19.3 0.3 12:39:03 12:47:54 R 6*60s 19.4 0.4 12:48:47 13:46:44 R 11*300s 19.7 0.2 --------------------------------------------------- We suggest the object reported in GCN6926 is the same star. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6930 SUBJECT: GRB 071013: 3rd TLS Epoch - constraints on variability DATE: 07/10/17 22:22:37 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, U. Laux & R. Filgas (TLS Tautenburg) report: During a serendipitous opening in the cloud cover, we observed the field of GRB 071013 (Marshall et al., GCN 6907) with the Tautenburg 1.34m Schmidt telescope under very good conditions, obtaining 4 300 second images in the Rc band at 4.2 days after the GRB, before clouds returned and shut us down. We use the same comparison star as given in Kann, Hoegner & Filgas (GCN 6917), and find the following magnitude of the possible variable source discovered by Kornienko et al. (GCN 6925) in a stacked image: Date Mid-Time Rc dRc 17.78693 4.28046 19.584 0.023 Thus, the magnitude remains unchanged in comparison to the second epoch (Kann et al., GCN 6926). Between 3.2 and 4.2 days, we rule out, at 3 sigma confidence level, any additional source (e.g., a rising SN component) brighter than R = 22.5. We also analyse the Kornienko Candidate in the stacked image of our first epoch (Kann, Hoegner & Filgas, GCN 6917). To summarize, from the three stacked images, we derive the following magnitudes of the possible host galaxy: Date Mid-Time Exposure Rc dRc 13.79254 0.28608 13 x 600 19.565 0.009 16.75845 3.25198 6 x 300 19.583 0.015 17.78693 4.28046 4 x 300 19.584 0.023 If the slight magnitude difference between epoch 1 and epoch 2 would be due to an additional source, it would have had R ~ 24 at 0.29 days. Assuming the detection by Kornienko et al. is real, and the "host" has R = 19.583, the "host-corrected" magnitude of the Kornienko Candidate is R = 18.56. The decay slope is then found to be alpha ~ 2 between 0.024 and 0.286 days. This is steep but not completely unrealistic. We are thus unable to rule out that the object found by Kornienko et al. may be a superposed faint afterglow, although contemporary measurements (Xin et al., GCN 6929) do not detect it. Since Swift seems to have not slewed at all and no position more precise than the refined BAT error circle is known (Palmer et al., GCN 6911), X-ray confirmation will probably not be forthcoming. This message may be cited.