GRB170813A

This page lists all entries on GRB170813A in GRBweb

Summary Fermi GBM IPN Swift GCN 21468 GCN 21469 GCN 21470 GCN 21472 GCN 21473 GCN 21480 GCN 21491

Summary table
Variable Value Source
GRB_name_Fermi GRB170813051
T0 1:13:08.291 UTC Fermi_GBM
ra 201.0576° Swift
decl -5.4908° Swift
pos_error 2.33e-04° Swift
T90 111.872 s Fermi_GBM
T90_error 4.871 s Fermi_GBM
T90_start 1:13:08.291 UTC Fermi_GBM
fluence 3.63e-06 erg/cm² Fermi_GBM
fluence_error 3.56e-08 erg/cm² Fermi_GBM
T100 111.872 s
GBM_located False
mjd 57978.05079040509 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB170813051
trigger_name bn170813051
ra 201.0579°
decl -5.4908°
pos_error 4.84e+00°
datum 2017-08-13
t_trigger 1:13:08.803 UTC
T90 111.872 s
T90_error 4.871 s
T90_start 1:13:08.291 UTC
fluence 3.63e-06 erg/cm²
fluence_error 3.56e-08 erg/cm²
flux_1024 2.36e+00 erg/cm²/s
flux_1024_error 1.79e-01 erg/cm²/s
flux_1024_time 7.04e-01 erg/cm²/s
flux_64 4.11e+00 erg/cm²/s
flux_64_error 9.63e-01 erg/cm²/s
IPN table
GRB_name GRB170813A
ra 201.0542°
decl -5.4667°
pos_error 5.00e-02°
Swift table
GRB_name GRB170813A
t_trigger 1:13:16 UTC
ra 201.0576°
decl -5.4908°
pos_error 2.33e-04°
T90 75.5 s
fluence 1.90e-06 erg/cm²
GCN 21468 table
GRB_name GRB170813A
GCN_number 21468
Detection_method Swift Det
t_trigger 1:13:16 UTC
ra 201.0540°
decl -5.4690°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21468 SUBJECT: GRB 170813A: Swift detection of a burst DATE: 17/08/13 01:30:09 GMT FROM: Kim Page at U.of Leicester K. L. Page (U Leicester), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Swift Team: At 01:13:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170813A (trigger=767563). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 201.054, -5.469 which is RA(J2000) = 13h 24m 13s Dec(J2000) = -05d 28' 07" 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 30 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~6 sec before the trigger. The XRT began observing the field at 01:15:30.5 UT, 134.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 201.0572, -5.4909 which is equivalent to: RA(J2000) = 13h 24m 13.73s Dec(J2000) = -05d 29' 27.1" with an uncertainty of 2.8 arcseconds (radius, 90% containment). This location is 79 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 consistent with the Galactic value of 2.73 x 10^20 cm^-2 (Willingale et al. 2013). The initial flux in the 2.5 s image was 5.59e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 143 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 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 0.04. Burst Advocate for this burst is K. L. Page (klp5 AT leicester.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.)
GCN 21469 table
GRB_name GRB170813A
GCN_number 21469
Detection_method Swift-XRT Det
ra 201.0576°
decl -5.4908°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21469 SUBJECT: GRB 170813A: Enhanced Swift-XRT position DATE: 17/08/13 07:32:14 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 1507 s of XRT Photon Counting mode data and 3 UVOT images for GRB 170813A, 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 = 201.05759, -5.49079 which is equivalent to: RA (J2000): 13h 24m 13.82s Dec (J2000): -05d 29' 26.9" with an uncertainty of 1.9 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 21470 table
GRB_name GRB170813A
GCN_number 21470
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21470 SUBJECT: GRB 170813A: Swift-XRT refined Analysis DATE: 17/08/13 14:41:34 GMT FROM: Kim Page at U.of Leicester A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester) and K. L. Page (U Leicester) report on behalf of the Swift-XRT team: We have analysed 10 ks of XRT data for GRB 170813A (Page et al. GCN Circ. 21468), from 124 s to 39.0 ks after the BAT trigger. The data comprise 26 s in Windowed Timing (WT) mode (the first 9 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. 21469). The light curve can be modelled with an initial power-law decay with an index of alpha=3.35 (+0.20, -0.18), followed by a break at T+796 s to an alpha of 0.9 (+0.5, -0.8). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.8 (+/-0.4). The best-fitting absorption column is 2.3 (+1.7, -1.3) x 10^21 cm^-2, in excess of the Galactic value of 2.7 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.3 (+1.7, -1.3) x 10^21 cm^-2 Galactic foreground: 2.7 x 10^20 cm^-2 Excess significance: 2.5 sigma Photon index: 1.8 (+/-0.4) If the light curve continues to decay with a power-law decay index of 0.9, the count rate at T+24 hours will be 4.2 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x 10^-14 (2.2 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00767563. This circular is an official product of the Swift-XRT team.
GCN 21472 table
GRB_name GRB170813A
GCN_number 21472
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21472 SUBJECT: GRB 170813A: RATIR Optical and NIR Observations DATE: 17/08/13 20:13:16 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 170813A (Page, et al., GCN 21468) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2017/08 13.15 to 2017/08 13.18 UTC (2.48 to 3.06 hours after the BAT trigger), obtaining a total of 0.36 hours exposure in the r and i bands and 0.15 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Osborne, et al., GCN 21469), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 22.46 i > 22.08 Z > 20.23 Y > 19.82 J > 19.38 H > 19.13 These magnitudes 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 Astronómico Nacional in San Pedro Mártir.
GCN 21473 table
GRB_name GRB170813A
GCN_number 21473
Detection_method Swift-BAT Det
ra 201.0570°
decl -5.5270°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21473 SUBJECT: GRB 170813A: Swift-BAT refined analysis DATE: 17/08/14 01:33:07 GMT FROM: Hans Krimm at NSF/NASA-GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester), 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 the recent telemetry downlink, we report further analysis of BAT GRB 170813A (trigger #767563) (Page, et al., GCN Circ. 21468). The BAT ground-calculated position is RA, Dec = 201.057, -5.527 deg which is RA(J2000) = 13h 24m 13.7s Dec(J2000) = -05d 31' 37.4" with an uncertainty of 3.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve shows a initial ragged pulse with a fast rise starting at about T-10 sec, peaking at T+3 sec and then decaying to near background by T+40, followed by a second weaker pulse from T+40 to T+80 sec. T90 (15-350 keV) is 75.5 +- 10.9 sec (estimated error including systematics). The time-averaged spectrum from T-9.2 to T+78.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.17 +- 0.14. The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.64 sec in the 15-150 keV band is 0.8 +- 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/767563/BA/
GCN 21480 table
GRB_name GRB170813A
GCN_number 21480
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21480 SUBJECT: GRB 170813A: Swift/UVOT Upper Limits DATE: 17/08/14 18:32:51 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170813A 144 s after the BAT trigger (Page et al., GCN Circ. 21468). No optical afterglow consistent with the enhanced XRT position (Osborne et al. GCN Circ. 21469) 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 144 293 147 >20.1 u_FC 302 551 246 >19.8 white 144 6769 727 >21.4 v 632 11867 1140 >19.3 b 557 6564 432 >20.7 u 302 6359 659 >20.4 w1 682 6154 413 >19.9 m2 4314 12580 1090 >20.5 w2 5339 10954 1145 >20.4
GCN 21491 table
GRB_name GRB170813A
GCN_number 21491
Detection_method Fermi GBM Det
t_trigger 1:13:25 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 21491 SUBJECT: GRB 170813A: Fermi GBM observation DATE: 17/08/15 21:25:46 GMT FROM: Suraj Poolakkil at UAH S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 01:13:25 UT on 13 August 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170813A (trigger 524279593/ 170813051), which was also detected by the Swift/BAT (Page et al. 2017, GCN 21468). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 41 degrees. The GBM light curve shows multiple pulses with a duration (T90) of about 112 s (50-300 keV). The time-averaged spectrum from T0-2.0 s to T0+23.6 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.52 +/- 0.11 and the cutoff energy, parameterized as Epeak, is 547 +/- 85 keV. The event fluence (10-1000 keV) in this time interval is (8.09 +/- 0.51)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.7 s in the 10-1000 keV band is 2.36 +/- 0.17 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." -- Suraj Poolakkil Fermi GBM Graduate Research Assistant Dept. of Space Science University of Alabama in Huntsville