GRBweb by P. Coppin

This page lists all entries on GRB090912A in GRBweb

Summary Fermi GBM IPN Swift GCN 9905 GCN 9906 GCN 9907 GCN 9908 GCN 9909 GCN 9910 GCN 9919

Summary table
Variable	Value	Source
GRB_name_Fermi	GRB090912660
T0	15:50:29 UTC	GCN_circulars,Swift Det
ra	188.0429°	Swift
decl	61.4846°	Swift
pos_error	1.81e-04°	Swift
T90	150.787 s	Fermi_GBM
T90_error	2.36 s	Fermi_GBM
T90_start	15:50:30.383 UTC	Fermi_GBM
fluence	8.28e-06 erg/cm²	Fermi_GBM
fluence_error	4.29e-08 erg/cm²	Fermi_GBM
T100	152.17 s
GBM_located	False
mjd	55086.66005787037	GCN_circulars,Swift Det

Fermi GBM table
GRB_name_Fermi	GRB090912660
trigger_name	bn090912660
ra	188.0400°
decl	61.4800°
pos_error	5.01e+00°
datum	2009-09-12
t_trigger	15:50:29.103 UTC
T90	150.787 s
T90_error	2.36 s
T90_start	15:50:30.383 UTC
fluence	8.28e-06 erg/cm²
fluence_error	4.29e-08 erg/cm²
flux_1024	2.25e+00 erg/cm²/s
flux_1024_error	2.51e-01 erg/cm²/s
flux_1024_time	9.06e+01 erg/cm²/s
flux_64	5.13e+00 erg/cm²/s
flux_64_error	1.45e+00 erg/cm²/s

IPN table
GRB_name	GRB090912A
ra	188.0917°
decl	61.5167°
pos_error	5.00e-02°

Swift table
GRB_name	GRB090912A
t_trigger	15:50:29 UTC
ra	188.0429°
decl	61.4846°
pos_error	1.81e-04°
T90	144.0 s
fluence	4.50e-06 erg/cm²

GCN 9905 table
GRB_name	GRB090912A
GCN_number	9905
Detection_method	Swift Det
t_trigger	15:50:29 UTC
ra	188.0920°
decl	61.5130°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9905 SUBJECT: GRB 090912: Swift detection of a burst DATE: 09/09/12 16:15:11 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC), M. M. Chester (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), V. Mangano (INAF-IASFPA), K. L. Page (U Leicester), P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA), R. L. C. Starling (U Leicester) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team: At 15:50:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090912 (trigger=362633). Swift executed a delayed slewed to the burst. The BAT on-board calculated location is RA, Dec 188.092, +61.513, which is RA(J2000) = 12h 32m 22s Dec(J2000) = +61d 30' 45" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two peaks at T+0 and at T+90 with a total duration of about 130 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began observing the field at 16:03:42.4 UT, 792.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 188.0422, 61.4843 which is equivalent to: RA(J2000) = 12h 32m 10.13s Dec(J2000) = +61d 29' 03.5" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 134 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.28e+20 cm^-2, Kalberla et al. 2005), with an excess column of 6.2 (+4.43/-3.60) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 795 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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.)

GCN 9906 table
GRB_name	GRB090912A
GCN_number	9906
Detection_method	Swift-XRT Det
ra	188.0430°
decl	61.4845°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9906 SUBJECT: GRB 090912: Enhanced Swift-XRT position DATE: 09/09/12 19:00:06 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 1374 s of XRT Photon Counting mode data and 2 UVOT images for GRB 090912, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 188.04297, +61.48454 which is equivalent to: RA (J2000): 12h 32m 10.31s Dec (J2000): +61d 29' 04.4" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.

GCN 9907 table
GRB_name	GRB090912A
GCN_number	9907
Detection_method	Optical
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9907 SUBJECT: GRB 090912 optical upper limit DATE: 09/09/13 10:17:51 GMT FROM: AAVSO GRB Network at AAVSO Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland) reports to the AAVSO International High Energy Network the following optical observations of the field of GRB090912 (GCN Circ. #9905, Ukwatta et al.): A. Oksanen reports an upper limit on the optical afterglow of CR=21.6, measured relative to USNO-A2.0 1500-05568008 (R=15.7). The X-ray afterglow position (Beardmore et al., GCN #9906) was observed using the 0.4-m Hankasalmi Observatory RC telescope with an SBIG STL-1001E CCD camera and clear filter. A total of 57 one-minute exposures were obtained, with the mid-point of the exposures at 2009 Sept 12 19:33 UT, approximately 3.7 hours post-burst. Two faint stars near the burst location are present in DSS2 images, but there is no transient source at the burst location to a limit of CR=21.6. A detailed report of these observations may be found at the following URL: ftp://ftp.aavso.org/grb/ArtoOksanen_GRB090912_2455087.38910_.txt A fits image is also available at ftp://ftp.aavso.org/grb/ArtoOksanen_GRB090912_2455087.38910_.fits The AAVSO thanks the Curry Foundation for its support of the AAVSO International High Energy Network.

GCN 9908 table
GRB_name	GRB090912A
GCN_number	9908
Detection_method	Swift-UVOT Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9908 SUBJECT: GRB 090912: Swift/UVOT Upper Limits DATE: 09/09/13 12:54:57 GMT FROM: Peter Curran at MSSL P.A. Curran (MSSL-UCL) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 090912 796s after the BAT trigger (Ukwatta et al., GCN 9905). No optical afterglow consistent with the enhanched Swift XRT position (Beardmore et al., GCN 9906) is detected in the UVOT exposures. Preliminary 3-sigma upper limits, using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627), for the first finding chart (FC) and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 796 946 147 >20.50 (FC) white 796 7707 608 >21.09 v 1129 8118 294 >19.04 b 1228 7502 254 >19.91 u 1204 7297 313 >19.58 w1 1179 7092 313 >19.82 m2 6688 8273 344 >19.78 w2 7713 7913 197 >19.78 The values quoted above are 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).

GCN 9909 table
GRB_name	GRB090912A
GCN_number	9909
Detection_method	Swift-BAT Det
ra	188.0460°
decl	61.4750°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9909 SUBJECT: GRB 090912, Swift-BAT refined analysis DATE: 09/09/13 18:49:52 GMT FROM: Tilan Ukwatta at GSFC/GWU T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink,we report further analysis of BAT GRB 090912 (trigger #362633) (Ukwatta, et al., GCN Circ. 9905). The BAT ground-calculated position is RA, Dec = 188.046, 61.475 deg which is RA(J2000) = 12h 32m 11.1s Dec(J2000) = +61d 28' 29.4" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%. The mask-weighted light curve shows two peaks. The first start around T-4 sec, shows three sub peaks at ~T+0 sec, ~T+4 sec, and ~T+7 sec, and ends around T+25 sec. The second peak starts at ~T+70 sec, peaks at ~T+88, and ends around T+145 sec. T90 (15-350 keV) is 144.0 +- 22.6 sec (estimated error including systematics). The time-averaged spectrum from T-15.9 to T+160.1 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.91 +- 0.44, and Epeak of 69.3 +- 19.5 keV (chi squared 42.50 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.5 +- 0.3 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+87.56 sec in the 15-150 keV band is 1.0 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.66 +- 0.09 (chi squared 52.84 for 57 d.o.f.). 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/362633/BA/

GCN 9910 table
GRB_name	GRB090912A
GCN_number	9910
Detection_method	Swift-XRT Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9910 SUBJECT: GRB 090912: Swift-XRT refined analysis DATE: 09/09/13 20:38:38 GMT FROM: Boris Sbarufatti at INAF-IASF-Pa Sbarufatti B., Mangano V. (INAF-IASFPA) and T. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: We have analyzed the first 22.5 ks of of Swift-XRT data of GRB 090912 (trigger 362633; Ukwatta, et al., GCN Circ. 9905). The data are entirely in Photon Counting (PC) mode, from T+806 s to T+66 ks. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 9906). The 0.3-10 keV X-ray light curve is best fitted by a power-law with decay index -0.75+/-0.03. Faint flaring activity is detected along the decay. If decaying at the present rate, the predicted rate for T+ 48h is 1.0e-2 counts/s. The average spectrum is best fit by a power-law with index 2.1+/-0.1. The absorbing column is NH = (5.2+/-0.7)E20 cm^-2, in excess with respect to the Galactic value of 1.3E20 cm^-2 (Kalberla et al. 2005). The average observed (unabsorbed) fluxes are 3.0(5.7)E-12 ergs cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00362633 . This circular is an official product of the Swift-XRT team.

GCN 9919 table
GRB_name	GRB090912A
GCN_number	9919
Detection_method	Optical
ra	12.0000°
decl	61.0000°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 9919 SUBJECT: GRB 090912: optical observation DATE: 09/09/16 22:13:56 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, V.Biryukov (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 090912 (Ukwatta et al., GCN 9905) with Zeiss-600 telescope of SAI MSU Crimean branch in R-filter on Sep.12 between (UT) 17:41:36 - 19:08:10. Within XRT error circle (Beardmore et al., GCN 9906) we do not detect any source. However in a stacked image we detect faint source at the coordinates RA(J2000)= 12 32 09.82 Dec(J2000)= +61 29 04.54 with uncertainty of 0.5 arcsec. It is 3.5" apart from XRT center of the circle of 1.8" radius. We suggest the detected source as afterglow candidate and urge deep observation to confirm variable nature of the source. The photometry of the source against nearby USNO-B1.0 star 1515-0196640 RA(J2000)= 12:32:18.77 Dec(J2000)= +61:30:00.3 assuming R=19.06 is following: T0+ Filter, Exposure, mag., err. (d) (s) 0.1086 R 4620 21.8 +/- 0.3