GRB150817A

This page lists all entries on GRB150817A in GRBweb

Summary Fermi GBM IPN Swift GCN 18143 GCN 18144 GCN 18145 GCN 18146 GCN 18147 GCN 18148 GCN 18149 GCN 18150 GCN 18153 GCN 18156 GCN 18158 GCN 18160

Summary table
Variable Value Source
GRB_name_Fermi GRB150817087
T0 2:05:07.632 UTC Fermi_GBM
ra 249.6311° Swift
decl -12.0529° Swift
pos_error 1.81e-04° Swift
T90 35.584 s Fermi_GBM
T90_error 1.145 s Fermi_GBM
T90_start 2:05:07.632 UTC Fermi_GBM
fluence 1.17e-05 erg/cm² Fermi_GBM
fluence_error 5.67e-08 erg/cm² Fermi_GBM
T100 44.168 s
GBM_located False
mjd 57251.08689388889 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB150817087
trigger_name bn150817087
ra 249.6429°
decl -12.0661°
pos_error 4.00e+00°
datum 2015-08-17
t_trigger 2:05:08.400 UTC
T90 35.584 s
T90_error 1.145 s
T90_start 2:05:07.632 UTC
fluence 1.17e-05 erg/cm²
fluence_error 5.67e-08 erg/cm²
flux_1024 1.57e+01 erg/cm²/s
flux_1024_error 4.34e-01 erg/cm²/s
flux_1024_time 1.63e+01 erg/cm²/s
flux_64 2.18e+01 erg/cm²/s
flux_64_error 1.95e+00 erg/cm²/s
IPN table
GRB_name GRB150817A
ra 249.6417°
decl -12.0667°
pos_error 5.00e-02°
Swift table
GRB_name GRB150817A
t_trigger 2:05:13 UTC
ra 249.6311°
decl -12.0529°
pos_error 1.81e-04°
T90 38.8 s
fluence 5.90e-06 erg/cm²
GCN 18143 table
GRB_name GRB150817A
GCN_number 18143
Detection_method Swift Det
t_trigger 2:05:13 UTC
ra 249.6430°
decl -12.0660°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18143 SUBJECT: GRB 150817A: Swift detection of a burst DATE: 15/08/17 02:14:02 GMT FROM: David Palmer at LANL V. D'Elia (ASDC), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), L. Izzo (URoma/ICRA), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 02:05:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150817A (trigger=652334). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 249.643, -12.066 which is RA(J2000) = 16h 38m 34s Dec(J2000) = -12d 03' 55" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of at least 50 sec. The peak count rate was ~17000 counts/sec (15-350 keV), at ~11 sec after the trigger. The XRT began observing the field at 02:06:18.2 UT, 64.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 249.63352, -12.05336 which is equivalent to: RA(J2000) = 16h 38m 32.04s Dec(J2000) = -12d 03' 12.1" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 56 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 in excess of the Galactic value (2.71 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 4.5 (+3.63/-3.05) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 1.27e-09 erg cm^-2 s^-1 (0.2-10 keV). There will be no prompt UVOT data available for this burst. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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.)
GCN 18144 table
GRB_name GRB150817A
GCN_number 18144
Detection_method Swift-XRT Other
ra 249.6333°
decl -12.0532°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18144 SUBJECT: GRB 150817A: RATIR Optical Afterglow Candidate DATE: 15/08/17 04:02:40 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 150817A (V. D'Elia, et al., GCN 18143) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2015/08 17.14 to 2015/08 17.16 UTC (1.29 to 1.70 hours after the BAT trigger), obtaining a total of 0.36 hours exposure in the r, i, and z bands. We find an uncatalogued source within the Swift-XRT error circle at RA, Dec = 16:38:31.98, -12:3:11.5 (J2000, +/-0.5"). In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections and upper limit (3-sigma): r = 21.50 +/- 0.20 i = 21.26 +/- 0.10 z > 17.83 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Further observations are planned. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 18145 table
GRB_name GRB150817A
GCN_number 18145
Detection_method Swift-BAT Det
ra 249.6313°
decl -12.0527°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18145 SUBJECT: GRB 150817A: Continued RATIR Observations, Revised Candidate DATE: 15/08/17 06:16:09 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We continue to observe the field of GRB 150817A (V. D'Elia, et al., GCN 18143) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2015/08 17.14 to 2015/08 17.25 UTC (1.29 to 3.93 hours after the BAT trigger), obtaining a total of 2.13 hours exposure in the r, i, and z bands. We note that the source reported in Butler et al. (GCN 18144) appears to have remained constant in flux over the time period quoted above, while an uncatalogued source just west of the XRT error circle has faded strongly as t^(-0.8+/-0.1). This second source is located at RA, Dec = 16:38:31.51, -12:03:9.6 (J2000, +/-0.5"). In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections and upper limit (3-sigma): r = 22.06 +/- 0.09 i = 21.49 +/- 0.07 z > 20.33 These magnitudes, corresponding to the midpoint of our observation, are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 18146 table
GRB_name GRB150817A
GCN_number 18146
Detection_method Swift-XRT Det
ra 249.6311°
decl -12.0529°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18146 SUBJECT: GRB 150817A: Enhanced Swift-XRT position DATE: 15/08/17 10:18:51 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 1629 s of XRT Photon Counting mode data and 4 UVOT images for GRB 150817A, 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 = 249.63108, -12.05293 which is equivalent to: RA (J2000): 16h 38m 31.46s Dec (J2000): -12d 03' 10.5" with an uncertainty of 1.7 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 18147 table
GRB_name GRB150817A
GCN_number 18147
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18147 SUBJECT: GRB 150817A: Swift-XRT refined Analysis DATE: 15/08/17 14:14:02 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), P. D'Avanzo (INAF-OAB), A. D'ai (INAF-IASFPA), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 11 ks of XRT data for GRB 150817A (D'Elia et al. GCN Circ. 18143), from 56 s to 29.2 ks after the BAT trigger. The data comprise 32 s in Windowed Timing (WT) mode (the first 7 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 18146). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=3.6 (+/-0.4). At T+104 s the decay flattens to an alpha of 0.57 (+0.06, -1.00) before breaking again at T+4285 s to a final decay with index alpha=1.07 (+/-0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.77 (+/-0.11). The best-fitting absorption column is 4.5 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 2.7 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.5 (+0.7, -0.6) x 10^21 cm^-2 Galactic foreground: 2.7 x 10^21 cm^-2 Excess significance: 4.6 sigma Photon index: 1.77 (+/-0.11) If the light curve continues to decay with a power-law decay index of 1.07, the count rate at T+24 hours will be 0.021 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.7 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00652334. This circular is an official product of the Swift-XRT team.
GCN 18148 table
GRB_name GRB150817A
GCN_number 18148
Detection_method Swift-BAT Det
ra 249.6350°
decl -12.0500°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18148 SUBJECT: GRB 150817A: Swift-BAT refined analysis DATE: 15/08/17 14:18:27 GMT FROM: Scott Barthelmy at NASA/GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (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 150817A (trigger #652334) (D'Elia, et al., GCN Circ. 18143). The BAT ground-calculated position is RA, Dec = 249.635, -12.050 deg, which is RA(J2000) = 16h 38m 32.3s Dec(J2000) = -12d 03' 01.7" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve shows multiple strong peaks starting at ~T-20, with the brightest peak at ~T+12 sec and ending at ~T+70 sec. T90 (15-350 keV) is 38.8 +- 2.1 sec (estimated error including systematics). The time-averaged spectrum from T-16.76 to T+53.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.78 +- 0.04. The fluence in the 15-150 keV band is 5.9 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+11.22 sec in the 15-150 keV band is 9.6 +- 0.3 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/652334/BA/
GCN 18149 table
GRB_name GRB150817A
GCN_number 18149
Detection_method Fermi GBM Det
t_trigger 2:05:08.400 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 18149 SUBJECT: GRB 150817A: Fermi GBM observation DATE: 15/08/17 15:37:57 GMT FROM: Hoi-Fung Yu at MPE H.-F. Yu (MPE) and P. Jenke (UAH) report on behalf of the Fermi GBM Team: "At 02:05:08.40 UT on 17 August 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150817A (trigger 461469912 / 150817087), which was also detected by the Swift/BAT (D'Elia et al. 2015, GCN 18143). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 102 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of multiple peaks with a duration (T90) of about 36 s (50-300 keV). The time-averaged spectrum from T0-10.240 s to T0+45.057 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.34 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 109.0 +/- 8.8 keV. The event fluence (10-1000 keV) in this time interval is (1.15 +/- 0.05)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+16.256 s in the 10-1000 keV band is 15.7 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 18150 table
GRB_name GRB150817A
GCN_number 18150
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18150 SUBJECT: GRB 150817A: Swift/UVOT Upper Limits DATE: 15/08/17 16:34:51 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150817A 3955 s after the BAT trigger (D'Elia et al., GCN Circ. 18143). No optical afterglow consistent with the enhanced X-ray position (Osborne et al. GCN Circ. 18146) or the optical position (Butler et al. GCN Circ. 18145) 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 first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 3955 4104 147 >20.5 white 3955 12079 930 >21.4 v 4111 28678 1278 >20.9 b 4932 17880 1723 >21.7 u 4727 23627 2613 >21.7 w1 4522 22957 2144 >21.0 w2 26865 27765 886 >20.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.48 in the direction of the burst (Schlegel et al. 1998).
GCN 18153 table
GRB_name GRB150817A
GCN_number 18153
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18153 SUBJECT: GRB 150817A: P60 Observations DATE: 15/08/18 13:30:21 GMT FROM: S. Bradley Cenko at NASA/GSFC S. B. Cenko (NASA/GSFC) and D. A. Perley (DARK) report on behalf of a larger collaboration: We observed the location of GRB150817A (DElia et al., GCN 18143) with the robotic Palomar 60 inch telescope (P60). Observations began at 3:35 UT on 2015 Aug 17 (~ 90 min after the Swift trigger time). We detect a faint source at the location of the (second) candidate optical afterglow from RATIR (Butler et al., GCN 18145). Using nearby point sources from the APASS survey, we measure an i-band magnitude of 21.42 +/- 0.11 in a stacked frame at a median epoch of dt = 125 min after the Swift trigger.
GCN 18156 table
GRB_name GRB150817A
GCN_number 18156
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18156 SUBJECT: GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation DATE: 15/08/18 16:29:47 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 150817A (D'Elia, et al., GCN 18143) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2015/08 18.16 to 2015/08 18.27 UTC (25.78 to 28.42 hours after the BAT trigger), obtaining a total of 1.77 hours exposure in the r, i, and z bands. The first source reported by Butler et al. (GCN 18144) has not faded since our first epoch of observations. The second source, reported by Butler et al. (GCN 18145), has continued to fade and is now only marginally detected. In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following marginal detections and upper limit (3-sigma): r = 23.8 0.4 i = 23.8 0.3 z > 20.2 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We note that the second source is consistent with the enhanced Swift-XRT error circle (Osborne et al. GCN 18146). This coincidence and the clear fading suggest that it is the afterglow of the GRB. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 18158 table
GRB_name GRB150817A
GCN_number 18158
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 18158 SUBJECT: GRB 150817A: LCOGT observations DATE: 15/08/18 18:03:36 GMT FROM: Simone Dichiara at Ferrara U/Italy S. Dichiara, C. Guidorzi (U. Ferrara), C.G. Mundell (U. Bath), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana) on behalf of a large collaboration report: The 1-m telescopes in Cerro Tololo (Chile) and McDonald (Texas) began observing Swift GRB 150817A (V. D'Elia, et al., GCN 18143). on August 17 at 03:16:31 UT, i.e. ~70 minutes since the BAT trigger, with the r' and i' filters. Further observations with the i' filter were performed using the 2-m Faulkes Telescope North ~400 min after the trigger. Within the enhanced XRT error circle (Osborne et al. GCN Circ. 18146) we find no optical counterpart to the following limiting magnitude: Mid time from Total Exp Filter Magnitude trigger (min) (s) ------------------------------------------------- 75.9 120x9 r' > 19.6 86.3 120x8 i' > 18.5 107.6 120x5 r' > 19.7 119.2 120x5 i' > 19.1 408.1 120x5 i' > 20.7 ------------------------------------------------- Our results are consistent with the previous observations reported by Butler et al. (GCN Circ. 18144) and Cenko et al. (GCN Circ. 18153). Magnitudes are calibrated against nearby USNO-B1 stars (R2 and I).
GCN 18160 table
GRB_name GRB150817A
GCN_number 18160
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18160 SUBJECT: GRB 150817A: AAO optical observations DATE: 15/08/18 19:09:15 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), V. Ayvazian (AAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150817A (D’Elia et al., GCN 18143) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Aug. 17 (UT) 17:00:31. Within the enhanced XRT error circle (Osborne et al., GCN 18146) we do not detect the optical afterglow (Butler et al., GCN 18145; Cenko et al., GCN 18153). In particular the magnitude of the first object (Butler et al., GCN 18144) is 21.6 +/- 0.2. Upper limit of the object is following Date UT start t-T0 Filter Exp. UL(3 sigam) (mid, days) (s) 2015-08-17 17:00:31 0.64432 None 24*120 22.4 The photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 0779-0405699 16.12 0779-0405721 16.40 0779-0405742 16.47 0779-0405723 16.94 0779-0405664 17.60