GRB170822A

This page lists all entries on GRB170822A in GRBweb

Summary IPN Swift GCN 21640 GCN 21642 GCN 21643 GCN 21647 GCN 21649 GCN 21651 GCN 21652 GCN 21654 GCN 21655 GCN 21679 GCN 21702 GCN 21947

Summary table
Variable Value Source
T0 9:11:51 UTC GCN_circulars,Swift Det
ra 94.3864° Swift
decl 55.0042° Swift
pos_error 1.81e-04° Swift
T90 64.0 s Swift
T90_start 9:11:51 UTC Swift
fluence 6.40e-06 erg/cm² Swift
T100 64.0 s
GBM_located False
mjd 57987.38322916667 GCN_circulars,Swift Det
IPN table
GRB_name GRB170822A
ra 94.3833°
decl 55.0167°
pos_error 5.00e-02°
Swift table
GRB_name GRB170822A
t_trigger 9:11:51 UTC
ra 94.3864°
decl 55.0042°
pos_error 1.81e-04°
T90 64.0 s
fluence 6.40e-06 erg/cm²
GCN 21640 table
GRB_name GRB170822A
GCN_number 21640
Detection_method Swift Det
t_trigger 9:11:51 UTC
ra 94.3820°
decl 55.0190°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21640 SUBJECT: GRB 170822A: Swift detection of a burst DATE: 17/08/22 09:32:56 GMT FROM: Kim Page at U.of Leicester A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), K. L. Page (U Leicester), T. Sakamoto (AGU), B. Sbarufatti (PSU), R. L. C. Starling (U Leicester) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team: At 09:11:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170822A (trigger=768939). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 94.382, +55.019 which is RA(J2000) = 06h 17m 32s Dec(J2000) = +55d 01' 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 70 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 09:14:34.2 UT, 163.2 seconds after the BAT trigger. The position determined from promptly downlinked data differs significantly from the on-board position, suggesting that the XRT may have centroided on a cosmic ray; the initial XRT position notice should be treated with caution. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 94.3869, 55.0040 which is equivalent to: RA(J2000) = 06h 17m 32.86s Dec(J2000) = +55d 00' 14.5" with an uncertainty of 2.0 arcseconds (radius, 90% containment). This location is 54 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 (1.91 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.6 (+2.37/-2.09) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 171 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 0.17. Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.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 21642 table
GRB_name GRB170822A
GCN_number 21642
Detection_method Optical
ra 94.3870°
decl 55.0045°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21642 SUBJECT: GRB 170822A:BOOTES-5/JGT optical afterglow candidate DATE: 17/08/22 11:12:19 GMT FROM: Juan Carlos Tello at IAA-CSIC J. C. Tello, A. J. Castro-Tirado, R. Cunniffe, B.-B. Zhang, Y. Hu and A. González-Rodríguez (IAA-CSIC), I. Carrasco (Univ. de Malaga), D. Hiriart, W. H. Lee (UNAM), S. Jeong and I. H. Park (SKKU) and P. Kubanek (Inst. of Physics, CZ) on behalf of a larger collaboration, report: The 60 cm BOOTES-5/JGT at Observatorio Astronómico Nacional in San Pedro Mártir (México) automatically responded in 7s (and 102s after the GRB onset) to the Swift trigger of GRB 170822A (Melandri et al., GCN 21640). The first unfiltered images (10 s exposures) were obtained at 09:13:38 UT (mid exposure). At the position of the Swift X-ray afterglow, we detect the likely optical afterglow at a magnitude of 18.3 (comparing to USNO-B1.0) and fading by 0.8 mag at 09:14:00 UT. The preliminary position is RA (J2000) = 6:17:32.89, Dec (J2000) = +55:00:16.13 (+/- 0".5). Further observations are being carried out. Spectroscopic observations are encouraged. We thank the staff at Observatorio Astronómico Nacional in San Pedro Mártir for its excellent support. [GCN OPS NOTE(22aug17): Per author's request, in the second line the "after the alert" was changed to "after the GRB onset".]
GCN 21643 table
GRB_name GRB170822A
GCN_number 21643
Detection_method Swift-XRT Det
ra 94.3867°
decl 55.0042°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21643 SUBJECT: GRB 170822A: Enhanced Swift-XRT position DATE: 17/08/22 14:29:01 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 2226 s of XRT Photon Counting mode data and 2 UVOT images for GRB 170822A, 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 = 94.38672, +55.00424 which is equivalent to: RA (J2000): 06h 17m 32.81s Dec (J2000): +55d 00' 15.3" 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 21647 table
GRB_name GRB170822A
GCN_number 21647
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21647 SUBJECT: GRB 170822A: Swift-XRT refined Analysis DATE: 17/08/22 17:25:14 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester) and A. Melandri report on behalf of the Swift-XRT team: We have analysed 8.8 ks of XRT data for GRB 170822A (Melandri et al. GCN Circ. 21640), from 153 s to 19.2 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 Beardmore et al. (GCN Circ. 21643). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=1.29 (+0.27, -0.23). At T+522 s the decay flattens to an alpha of -0.77 (+0.28, -0.35). The light curve breaks again at T+1393 s to a decay with alpha=0.81 (+0.09, -0.11), before a final break at T+6591 s s after which the decay index is 1.89 (+0.37, -0.14). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.84 (+/-0.08). The best-fitting absorption column is 3.5 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 1.9 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 4.2 x 10^-11 (5.9 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.5 (+/-0.4) x 10^21 cm^-2 Galactic foreground: 1.9 x 10^21 cm^-2 Excess significance: 6.6 sigma Photon index: 1.84 (+/-0.08) If the light curve continues to decay with a power-law decay index of 1.89, the count rate at T+24 hours will be 6.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.9 x 10^-13 (4.1 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00768939. This circular is an official product of the Swift-XRT team.
GCN 21649 table
GRB_name GRB170822A
GCN_number 21649
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21649 SUBJECT: GRB 170822A: Swift/UVOT Upper Limits DATE: 17/08/22 18:07:41 GMT FROM: Sam Emery at MSSL-UCL S.W.K. Emery (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170822A 171 s after the BAT trigger (Melandri et al., GCN Circ. 21640). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 21643) and the optical position (Tello et al., GCN Circ. 21642) 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 171 321 148 >20.4 white 529 1894 284 >21.3 v 406 1936 165 >19.2 b 504 1870 156 >20.2 u 480 1845 156 >19.8 uvw1 455 1820 155 >19.7 uvm2 604 1101 39 >18.1 uvw2 381 1921 175 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.17 in the direction of the burst (Schlegel et al. 1998).
GCN 21651 table
GRB_name GRB170822A
GCN_number 21651
Detection_method Swift-BAT Det
ra 94.3750°
decl 55.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21651 SUBJECT: GRB 170822A: Swift-BAT refined analysis DATE: 17/08/22 22:12:25 GMT FROM: Amy Lien at GSFC T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (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 170822A (trigger #768939) (Melandri et al., GCN Circ. 21640). The BAT ground-calculated position is RA, Dec = 94.375, 55.000 deg which is RA(J2000) = 06h 17m 29.9s Dec(J2000) = +54d 59' 59.0" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 12%. The mask-weighted light curve shows a multi-peaked structure that starts at ~ T-15 s and ends at ~T+60 s. T90 (15-350 keV) is 64 +- 16 sec (estimated error including systematics). The time-averaged spectrum from T-15.62 to T+64.38 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.80 +- 0.09. The fluence in the 15-150 keV band is 6.4 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+7.88 sec in the 15-150 keV band is 4.2 +- 0.7 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/768939/BA/
GCN 21652 table
GRB_name GRB170822A
GCN_number 21652
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 21652 SUBJECT: GRB 170822A: MITSuME Akeno Optical Observation DATE: 17/08/23 07:15:59 GMT FROM: Katsuhiro L. Murata at Nagoya U K. L. Murata, Y. Saito, R. Itoh, Y. Tachibana, T. Yoshii, S. Harita, K. Morita, T. Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 170822A (Melandri et al., GCN Circular #21640) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2017-08-22 16:27:38.15 UT . We did not find any new point source within enhanced XRT circle (Evans et al., GCN Circular #21643) in all three bands. We obtained following limits for the magnitudes. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- ~7.21 16:48:33.09 2280 >20.8 >20.1 >18.9 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.
GCN 21654 table
GRB_name GRB170822A
GCN_number 21654
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21654 SUBJECT: GRB 170822A: AbAO optical upper limit DATE: 17/08/23 13:14:20 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AbAO), A. Pozanenko (IKI), A. Volnova (IKI), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 170822A (Melandri et al., GCN 21640)) with AS-32 (0.7m) telescope of Abastumani Observatory starting on August, 22 (UT) 22:43:12. We obtained several unfiltered images of the field. Within enhanced XRT error circle (Beardmore et al., GCN 21643) we do not detect the afterglow candidate (Tello et al, GCN 21642). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err UpLim (3 sigma) (mid, days) (s) 2017-08-22 22:43:12 0.58255 CR 32*60 n/d n/d 22.2 Photometry is based on nearby USNO-B1.0 stars R2 magnitudes USNO-B.1_id R2 1450-0165651 15.44 1450-0165657 15.54 1450-0165669 16.19 1450-0165558 16.58 1450-0165549 15.60 1450-0165573 15.28 1449-0164981 16.05 A finding chart can be found at http://grb.rssi.ru/GRB170822A/GRB170822A_AAO_170822+Bootes-OT.png
GCN 21655 table
GRB_name GRB170822A
GCN_number 21655
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21655 SUBJECT: GRB 170822A: RATIR Optical and NIR Observations DATE: 17/08/23 13:59:54 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 (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 170822A (Melandri et al., GCN Circ. 21640) 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 23.44 to 2017/08 23.48 UTC (25.45 to 26.38 hours after the BAT trigger), obtaining a total of 0.69 hours exposure in the r and i bands and 0.30 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle, in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 23.37 i > 22.87 Z > 21.99 Y > 21.56 J > 21.28 H > 20.82 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The bright but rapidly-fading optical transient reported by Tello et al. (GCN Circ. 21642) is not seen in our images. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.
GCN 21679 table
GRB_name GRB170822A
GCN_number 21679
Detection_method Konus-Wind Det
t_trigger 9:11:51.022 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 21679 SUBJECT: Konus-Wind observation of GRB 170822A DATE: 17/08/24 15:43:32 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The long-duration, soft-spectrum GRB 170822A (Swift-BAT detection: Melandri et al., GCN Circ. 21640) triggered Konus-Wind at T0=33111.022 s UT (09:11:51.022). The burst light curve shows a multipeaked structure which starts at ~T0-10.5 s and has a total duration of ~62 s. The emission is seen up to ~1 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170822_T33111/ As observed by Konus-Wind, the burst had a fluence of 8.57(-0.76,+0.88)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.266 s, of 1.66(-0.60,+0.60)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+57.6 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.20(-0.38,+0.48) and Ep = 70(-12,+12) keV (chi2 = 57/62 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.4 (chi2 = 55/61 dof). The spectrum near the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: with alpha = -1.17(-0.26,+0.30) and Ep = 90(-11,+13) keV (chi2 = 51/61 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.8 (chi2 = 51/60 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 21702 table
GRB_name GRB170822A
GCN_number 21702
Detection_method AstroSat CZTI
t_trigger 9:11:52 UTC
T90 62.3 s
Circular_text TITLE: GCN CIRCULAR NUMBER: 21702 SUBJECT: GRB 170822A: AstroSat CZTI detection DATE: 17/08/25 19:15:22 GMT FROM: Vidushi Sharma at IUCAA V. Sharma (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed clear detection of short GRB 170822A (Swift detection: Melandri A. et al, GCN Circ. 21640) in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 09:11:52.0 UT, around 1 s after the Swift/BAT trigger. The measured peak count rate is 163.1 counts/s above the background in combined data of four quadrants, with a total 369 counts. The local mean background count rate was 399.0 counts/s. Using cumulative rates, we measure a T90 of 62.3 s. It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection in the 100-500 keV energy range. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN 21947 table
GRB_name GRB170822A
GCN_number 21947
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21947 SUBJECT: GRB 170822A: 15 GHz upper limits from AMI DATE: 17/10/01 20:07:24 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 170822A (Melandri et al., GCN 21640) as part of the 4pisky program, and subsequent follow up observations were obtained up to 30 days post-burst. Our observations at 15 GHz on 2017 Aug 22.42, Aug 25.34, Aug 26.34, Aug 30.37, Sep 03.28 and Sep 20.26 (UT) do not reveal any radio source at the XRT location (Beardmore et al., GCN 21643), with 3sigma upper limits of 165 uJy, 132 uJy, 138 uJy, 210 uJy, 210 uJy and 138 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.