//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12327 SUBJECT: GRB 110905A: Swift detection of a burst DATE: 11/09/05 06:34:30 GMT FROM: Scott Barthelmy at NASA/GSFC C. Pagani (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), C. J. Mountford (U Leicester), K. L. Page (U Leicester), C. J. Saxton (UCL-MSSL) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team: At 05:48:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110905A (trigger=502415). Swift did not slew because of the Moon observing constraint. The BAT on-board calculated location is RA, Dec 278.954, -19.318, which is RA(J2000) = 18h 35m 49s Dec(J2000) = -19d 19' 03" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve is not available at this time. Due to an observing constraint, Swift cannot slew to the BAT position, before 12:33 UT on 2011 September 8. There will thus be no XRT or UVOT data for this trigger. Burst Advocate for this burst is C. Pagani (cp232 AT star.le.ac.uk). 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: 12328 SUBJECT: GRB 110905A: KAIT observations DATE: 11/09/05 06:47:08 GMT FROM: Weidong Li at UC Berkeley KAIT/LOSS W. Li and A. V. Filippenko, University of California, Berkeley, on behalf of the KAIT GRB team, report: The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory observed GRB 110905A (Pagani et al., GCN 12327). The automatic sequence started at 06:18:04 UT, ~ 30 minutes after the BAT trigger. Our image processing pipeline found a new object within the BAT error circle, with the following position: R. A. = 18:35:43.44 DEC. = -19:19:10.5 (J2000), The object has a magnitude of R ~ 16 at 06:19:48 UT ( calibrated to USNO B1). Observations are still ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12329 SUBJECT: GRB 110905A: Potential BAT trigger on MAXI J1836-194 DATE: 11/09/05 08:04:30 GMT FROM: Derek Fox at PSU Derek B. Fox (Penn State) reports: "The new R~16 mag optical source identified by Li & Filippenko (GCN 12328) in their follow-on observations of the recent Swift BAT image trigger 502415 / GRB 110905A (Pagani et al., GCN 12327), is almost certainly the optical counterpart to the recently-discovered X-ray transient MAXI J1836-194 (Negoro et al., ATel #3611). This likely black hole X-ray binary system has an associated optical (Kennea et al., ATel #3613), NIR (Rau, Greiner & Sudilovsky, ATel #3619) and radio (Miller-Jones et al., ATel #3628) counterpat with coordinate position (most accurately known from EVLA observations) consistent to <~1 arcsec with the optical source of Li & Fillippenko. Given that BAT trigger #502415 is a BAT image trigger with localization consistent with the position of the new transient, this raises the question of whether BAT trigger #502415 was generated by high-energy variability of MAXI J1836-194 itself rather than being due to a bona fide gamma-ray burst. If GRB 110905A is a genuine gamma-ray burst -- distinct from and unrelated to MAXI J1836-194 -- the source reported by Li & Fillippenko, being the optical counterpart of MAXI J1836-194, is almost certainly not the burst's optical afterglow. The author cites a private communication from J. Greiner as first to point out this possible interpretation of events." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12330 SUBJECT: GRB 110905A / X-ray transient MAXI J1836-194: TNT optical observation DATE: 11/09/05 14:32:48 GMT FROM: L.P. Xin at NAOC L.P. Xin, M,Zhai, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng, C. Wu, X. H. Han on behalf of EAFON report: We began to observe GRB110905A (Pagani et al., GCN 12327) with Xinglong TNT telescope at 11:25:29 (UT), 5.6 hour after the burst. Ten R-band images were obtained. The optical source reported by Li & Filippenko (GCN 12328) was clearly detected in all images with a brightness of ~15.5 mag in R band ( relative to USNO B1.0 R2 magntidue). This message may be cited. For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org/grb/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12331 SUBJECT: MAXI J1836-194 (originally GRB 110905A): Swift-BAT refined analysis DATE: 11/09/05 17:40:23 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC) (i.e. the Swift-BAT team): Using the data set from T+592 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT trigger #502415 (Pagani, et al., GCN Circ. 12327). The BAT ground-calculated position is RA, Dec = 278.958, -19.269 deg, which is RA(J2000) = 18h 35m 49.9s Dec(J2000) = -19d 16' 07.5" with an uncertainty of 3.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. Because this was a long image trigger (26 minutes), the event-by-event data just before, during, and for 592 sec after the trigger time was overwritten in the ring buffer, and as such, it is not possible to construct a lightcurve for the early phase of this event. Starting at T+590, the lightcurve shows a low-level persistant emission out to T+963 sec. The time-averaged spectrum from T+590 to T+963 sec can be fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.39. The fluence in the 15-150 keV band is 7.8 +- 2.0 x 10^-7 erg/cm2. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/502415/BA/ Given the (a) the long and constant hard x-ray emission (in the later phase) of this event, (b) the proximity to the Galactic Bulge, (c) the proximity to the MAXI J1836-194; we believe this trigger to be due to the MAXI source and not due to a GRB (as has been pointed out by J.Greiner (pri.comm.) and D.Fox (GCN 12329)). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12411 SUBJECT: GRB 110905A / MAXI J1836-194: optical monitoring DATE: 11/10/01 16:31:58 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), A. Volnova (SAI MSU), M. Andreev (Terskol Branch of Institute of Astronomy), V. Rumyantsev (CrAO), D. Shakhovskoy (CrAO), V. Biryukov (SAI MSU & CrAO), A. Sergeev (Terskol Branch of Institute of Astronomy) on behalf of larger GRB follow up collaboration report: We started a monitoring campaign of MAXI J1836-194 (Negoro et al., ATel 3611) after Swift triggers #502415 (=GRB110905A, Pagani et al., GCN 12327). Till now observations were obtained with Zeiss-600 (Mt. Terskol), AZT-11 (CrAO), Zeiss-600 and ZTE (SAI MSU) in the R and B filters. We clearly detect significant optical variability of the source of MAXI J1836-194, and at least one peak of our light curve (Sep. 19.80) coincides with a peak of radio light curve of MAXIJ1836-194 at 4.8 GHz (Trushkin et al., ATel. 3656). The light curve (Sep. 5 - Sep. 26) can be found at http://grb.rssi.ru/GRB110905A=MAXI_J1836-194/MAXIJ1836-194_lc_opt.png Observations will be continued.