GRB120805A

This page lists all entries on GRB120805A in GRBweb

Summary IPN Swift GCN 13588 GCN 13589 GCN 13590 GCN 13591 GCN 13592 GCN 13594 GCN 13598 GCN 13638 GCN 13639 GCN 13651

Summary table
Variable Value Source
T0 21:28:09 UTC GCN_circulars,Swift Det
ra 216.5384° Swift
decl 5.8253° Swift
pos_error 3.49e-04° Swift
T90 48.0 s Swift
T90_start 21:28:09 UTC Swift
fluence 8.20e-07 erg/cm² Swift
redshift 3.1000
T100 48.0 s
GBM_located False
mjd 56144.89454861111 GCN_circulars,Swift Det
IPN table
GRB_name GRB120805A
ra 216.5333°
decl 5.8000°
pos_error 5.00e-02°
redshift 3.1000
Swift table
GRB_name GRB120805A
t_trigger 21:28:09 UTC
ra 216.5384°
decl 5.8253°
pos_error 3.49e-04°
T90 48.0 s
fluence 8.20e-07 erg/cm²
redshift 3.1000
GCN 13588 table
GRB_name GRB120805A
GCN_number 13588
Detection_method Swift Det
t_trigger 21:28:09 UTC
ra 216.5330°
decl 5.8020°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13588 SUBJECT: GRB 120805A: Swift detection of a burst DATE: 12/08/05 21:57:05 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), S. T. Holland (STScI), J. A. Kennea (PSU), O. M. Littlejohns (U Leicester), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 21:28:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120805A (trigger=530031). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 216.533, +5.802 which is RA(J2000) = 14h 26m 08s Dec(J2000) = +05d 48' 08" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 50 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 21:30:13.0 UT, 123.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 216.54056, 5.82571 which is equivalent to: RA(J2000) = 14h 26m 09.73s Dec(J2000) = +05d 49' 32.6" with an uncertainty of 4.3 arcseconds (radius, 90% containment). This location is 89 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.22 x 10^20 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 90 seconds with the White filter starting 126 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 0.03. Burst Advocate for this burst is E. Troja (eleonora.troja AT 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.)
GCN 13589 table
GRB_name GRB120805A
GCN_number 13589
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 13589 SUBJECT: GRB 120805A: TAROT Calern observatory optical observations DATE: 12/08/05 22:01:24 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 120805A detected by SWIFT (trigger 530031) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 77.2s after the GRB trigger (19.3s after the notice). The elevation of the field decreased from 20 degrees above horizon and weather conditions were moonlight. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any OT in the BAT error box with a limiting magnitude of: t0+77.2s to t0+137.2s : R > 15.9 The second image is 30.0s exposure in tracking mode: t0+152.6s to t0+182.6s : R > 16.2 We co-added a series of exposures: t0+152.6s to t0+851s : R > 17.4 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=353.7578 lat=+58.9832 and the galactic extinction in R band is about 0.1 magnitude estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited.
GCN 13590 table
GRB_name GRB120805A
GCN_number 13590
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 13590 SUBJECT: GRB120805A: Liverpool Telescope observations DATE: 12/08/05 23:35:45 GMT FROM: David Bersier at Liverpool John Moores U David Bersier (LJMU), Drejc Kopac (Ljubljana) report The Liverpool Telescope (La Palma) started robotic observations of GRB 120805A 3 minutes after detection by Swift (Troja et al, GCN 13588). We find no credible afterglow candidate in the XRT error circle. We find upper limits of 18.9 in the r band 30 minutes after burst and 18.7 in the i band 47 minutes after burst. [GCN OPS NOTE(06aug12): Per author's request, in the Subject-line the "120521C" has been changed to "120805A".]
GCN 13591 table
GRB_name GRB120805A
GCN_number 13591
Detection_method Optical
ra 216.5380°
decl 5.8255°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13591 SUBJECT: GRB 120805A: 1.23m CAHA observations DATE: 12/08/05 23:49:45 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), N. Huelamo (CAB-CSIC), R. Sanchez-Ramirez (IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC, DARK), T. Kruehler (DARK), A.J. Castro-Tirado (IAA-CSIC), J.C. Tello (IAA-CSIC), M. Jelinek (IAA-CSIC), report on behalf of a larger collaboration: "I-band observations conducted with the Calar Alto 1.23m telescope at 21:41:19.1--22:04:02.4 UT (obs started ~13 minutes post GRB) for GRB 120805A reveal no object inside the XRT position (GCN Circ. 13588) down to I~18 (Vega). However, we note the presence an object located at RA(J2000)=14:26:09.12, DEC(J2000)=05:49:31.7 (error of ~0.5" in both coordinates) with a magnitude of I~17.5 which seems not to be at the SDSS. Given the lack of a refined XRT position yet, we are cautious about the possible relation of this object with the GRB 120805A optical afterglow."
GCN 13592 table
GRB_name GRB120805A
GCN_number 13592
Detection_method Swift-XRT Other
ra 216.5411°
decl 5.8255°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13592 SUBJECT: GRB 120805A: Swift-XRT refined Analysis DATE: 12/08/06 09:57:04 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), M.C. Stroh (PSU) and E. Troja report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 120805A (Troja et al. GCN Circ. 13588), from 126 s to 13.6 ks after the BAT trigger. The data comprise 115 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 216.5411, +5.82554 which is equivalent to: RA (J2000): 14 26 09.86 Dec(J2000): +05 49 31.9 with an uncertainty of 3.6 arcsec (radius, 90% confidence). The light curve can be modelled with a series of power-law decays. The light curve initially rises, with an index alpha=-1.497 (+0.951, -0.003). At T+191 s it breaks to an alpha of 2.33 (+0.14, -0.12) before breaking again at T+2805 s to a final decay with index alpha=0.3 (+/-0.7). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.43 (+0.22, -0.20). The best-fitting absorption column is 2.1 (+0.9, -0.8) x 10^21 cm^-2, in excess of the Galactic value of 2.2 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.1 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 2.1 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 2.2 x 10^20 cm^-2 Excess significance: 3.7 sigma Photon index: 1.43 (+0.22, -0.20) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00530031. This circular is an official product of the Swift-XRT team.
GCN 13594 table
GRB_name GRB120805A
GCN_number 13594
Detection_method Swift-BAT Det
ra 216.5360°
decl 5.8530°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13594 SUBJECT: GRB 120805A: Swift-BAT refined analysis DATE: 12/08/06 13:44:59 GMT FROM: Scott Barthelmy at NASA/GSFC 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), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), E. Troja (NASA/GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+330 sec from the recent telemetry downlink, we report further analysis of BAT GRB 120805A (trigger #530031) (Troja, et al., GCN Circ. 13588). The BAT ground-calculated position is RA, Dec = 216.536, 5.853 deg, which is RA(J2000) = 14h 26m 08.5s Dec(J2000) = +05d 51' 09.7" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 37%. The mask-weighted light curve shows several overlapping peaks starting at ~T-8 sec, peaking at ~T+8 sec, and returning to baseline around T+110 sec. T90 (15-350 keV) is 48.00 +- 22.63 sec (estimated error including systematics). The time-averaged spectrum from T-15.39 to T+32.61 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.20 +- 0.28. The fluence in the 15-150 keV band is 8.2 +- 1.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+8.11 sec in the 15-150 keV band is 0.37 +- 0.2 ph/cm2/sec. 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/530031/BA/
GCN 13598 table
GRB_name GRB120805A
GCN_number 13598
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 13598 SUBJECT: GRB 120805A: Swift/UVOT Upper Limits DATE: 12/08/06 19:09:10 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 120805A 127 s after the BAT trigger (Troja et al., GCN Circ. 13588). No optical afterglow consistent with the refined XRT position (Burrows et al., GCN Circ. 13592) is detected in the initial UVOT exposures. 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 127 7557 579 >22.0 v 1339 11924 1248 >20.8 b 1265 7352 490 >21.5 u 1240 7146 490 >20.5 w1 1216 13611 1253 >21.3 m2 1364 12829 1141 >21.6 w2 1487 7763 432 >21.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN 13638 table
GRB_name GRB120805A
GCN_number 13638
Detection_method Swift-XRT Det
ra 216.5384°
decl 5.8252°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13638 SUBJECT: GRB 120805A: Enhanced Swift-XRT position DATE: 12/08/14 08:26:46 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: We have reinvestigated the XRT position of GRB 120805A. Using 2.6 ks of XRT Photon Counting mode data and 2 UVOT images, 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 = 216.53836, 5.82525 which is equivalent to: RA (J2000): 14 26 09.21 Dec (J2000): +05 49 30.9 with an uncertainty of 2.7 arcsec (radius, 90% confidence). This position is 10" from the unenhanced XRT position reported in GCN Circ. 13592. The size of the astrometric correction, which is responsible for this shift, was such that the enhanced position was initially rejected and not circulated automatically. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This corrected position is our best XRT position, and is 1.5 arcsec from the optical counterpart proposed in GCN Circ. 13591, supporting the identification of that source as the afterglow. We thank Daniele Malesani for drawing this to our attention. This circular is an official product of the Swift-XRT team.
GCN 13639 table
GRB_name GRB120805A
GCN_number 13639
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 13639 SUBJECT: GRB 120805A: optical afterglow confirmation from the NOT DATE: 12/08/14 12:10:51 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani, T. Kruehler (DARK/NBI), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), D. Xu (WIS), N. R. Tanvir (Univ. Leicester), J. Gorosabel (IAA/CSIC), P. Jakobsson (Univ. Iceland), S. Geier (NOT and DARK/NBI), T. Pursimo (NOT), report on behalf of a larger collaboration. We observed the field of GRB 120805A (Troja et al., GCN 13588) on two epochs with the NOT optical telescope, located in La Palma (Canary Islands). The two observations were carried out on mean dates Aug 5.936 and 13.896 UT, that is 1.0 hr and 8.0 days after the GRB, respectively. The source first noticed by Gorosabel et al. (GCN 13591) is detected in both our images, and it varied significantly between the two epochs, as well as compared to the CAHA report (Gorosabel et al., GCN 13591). We note that the object position is now fully consistent with the revised XRT error circle (Evans, GCN 13638). We thus conclude that this source is the optical afterglow of GRB 120805A. The source varied by only about 2 mag between the two NOT epochs (corresponding to a power-law decay slope of ~0.3), suggesting that in the later image the host galaxy could be contributing to the total light. A picture showing the two NOT epochs is posted at this URL: http://www.astro.ku.dk/~malesani/GRB/120805A/GRB120805A_comparison.jpg We thank Phil Evans for discussion about the XRT localization of this afterglow.
GCN 13651 table
GRB_name GRB120805A
GCN_number 13651
Detection_method Optical
ra 216.5380°
decl 5.8256°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13651 SUBJECT: GRB 120805A: Liverpool Telescope optical candidate detection DATE: 12/08/15 07:30:58 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara) and C.G. Mundell (LJMU) report on behalf of a large collaboration: The Liverpool Telescope automatically observed GRB 120805A (Troja et al. GCN Circ. 13588) as previously reported (Bersier et al GCN Circ. 13590). We also detected the optical candidate identified by Gorosabel et al. (GCN Circ. 13591) at the following position, within the UVOT-enhanced XRT error circle (Evans et al. GCN Circ. 13638): RA(J2000) = 14:26:09.11 Dec(J2000)= +05:49:32.1 with an uncertainty of 1". The optical afterglow candidate is detected in both r' and i' filters with the following magnitudes: Mid time from Total Exp Filter Magnitude trigger (min) (s) ------------------------------------------------ 16.0 6x10 r' 20.9 +- 0.3 50.0 3x120 i' 20.9 +- 0.2 ------------------------------------------------ Magnitudes are calibrated against nearby USNOB-1 stars.