Gamma-ray Burst 200809B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 09 Aug 20 15:41:51 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      47
  TRIGGER_NUM:     618680492
  GRB_RA:           27.133d {+01h 48m 32s} (J2000),
                    27.292d {+01h 49m 10s} (current),
                    26.747d {+01h 46m 59s} (1950)
  GRB_DEC:         -63.500d {-63d 30' 00"} (J2000),
                   -63.398d {-63d 23' 52"} (current),
                   -63.748d {-63d 44' 52"} (1950)
  GRB_ERROR:       8.85 [deg radius, statistical plus systematic]
  GRB_INTEN:       333 [cnts/sec]
  DATA_SIGNIF:     10.70 [sigma]
  INTEG_TIME:      1.024 [sec]
  GRB_DATE:        19070 TJD;   222 DOY;   20/08/09
  GRB_TIME:        56487.13 SOD {15:41:27.13} UT
  GRB_PHI:         247.00 [deg]
  GRB_THETA:       100.00 [deg]
  DATA_TIME_SCALE: 1.0240 [sec]
  HARD_RATIO:      0.34
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      96%  GRB
  2nd_MOST_LIKELY:   3%  Generic Transient
  DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
  SUN_POSTN:       139.95d {+09h 19m 49s}  +15.59d {+15d 35' 06"}
  SUN_DIST:        113.98 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
  MOON_POSTN:       25.02d {+01h 40m 04s}   +5.53d {+05d 31' 51"}
  MOON_DIST:        68.95 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      292.53,-52.46 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      336.91,-64.43 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_lc_medres34_bn200809654.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 241.03,-10.53 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 09 Aug 20 15:42:09 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      60
  TRIGGER_NUM:     618680492
  GRB_RA:           24.320d {+01h 37m 17s} (J2000),
                    24.476d {+01h 37m 54s} (current),
                    23.940d {+01h 35m 46s} (1950)
  GRB_DEC:         -66.270d {-66d 16' 11"} (J2000),
                   -66.166d {-66d 09' 55"} (current),
                   -66.524d {-66d 31' 26"} (1950)
  GRB_ERROR:       4.77 [deg radius, statistical only]
  DATA_SIGNIF:     16.10 [sigma]
  DATA_INTERVAL:   1.024 [sec]
  GRB_DATE:        19070 TJD;   222 DOY;   20/08/09
  GRB_TIME:        56487.13 SOD {15:41:27.13} UT
  GRB_PHI:         247.00 [deg]
  GRB_THETA:       103.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   4173 (Gnd S/W Version number)
  SUN_POSTN:       139.95d {+09h 19m 49s}  +15.58d {+15d 35' 06"}
  SUN_DIST:        114.40 [deg]   Sun_angle= 7.7 [hr] (West of Sun)
  MOON_POSTN:       25.02d {+01h 40m 05s}   +5.53d {+05d 31' 54"}
  MOON_DIST:        71.70 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      295.75,-50.21 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      329.96,-64.94 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_lc_medres34_bn200809654.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_618680492.fits
  COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
  COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 09 Aug 20 15:50:50 UT
  NOTICE_TYPE:     Fermi-GBM Final Position
  RECORD_NUM:      0
  TRIGGER_NUM:     618680492
  GRB_RA:          359.750d {+23h 59m 00s} (J2000),
                     0.015d {+00h 00m 04s} (current),
                   359.097d {+23h 56m 23s} (1950)
  GRB_DEC:         -76.910d {-76d 54' 35"} (J2000),
                   -76.795d {-76d 47' 42"} (current),
                   -77.188d {-77d 11' 17"} (1950)
  GRB_ERROR:       3.39 [deg radius, statistical only]
  GRB_DATE:        19070 TJD;   222 DOY;   20/08/09
  GRB_TIME:        56487.13 SOD {15:41:27.13} UT
  GRB_PHI:         247.00 [deg]
  GRB_THETA:       116.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   41731 (Gnd S/W Version number)
  SUN_POSTN:       139.96d {+09h 19m 50s}  +15.58d {+15d 34' 60"}
  SUN_DIST:        115.46 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
  MOON_POSTN:       25.09d {+01h 40m 21s}   +5.56d {+05d 33' 36"}
  MOON_DIST:        83.59 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:      306.77,-39.83 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      300.25,-63.28 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_lc_medres34_bn200809654.gif
  LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_locplot_all_bn200809654.png
  COMMENTS:        Fermi-GBM Final Position.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
  COMMENTS:        This notice was generated completely by automated pipeline processing.  
  COMMENTS:        This is likely a Long GRB.  
  

• GCN Circular #28236
  The Fermi GBM team reports the detection of a likely LONG GRB
  At 15:41:27 UT on 9 Aug 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200809B (trigger 618680492.129862 / 200809654).
  The on-ground calculated location, using the Fermi GBM trigger data, is RA = 359.8, Dec = -76.9 (J2000 degrees, equivalent to J2000 23h 59m, -76d 54'), with a statistical uncertainty of 3.4 degrees.
  The angle from the Fermi LAT boresight is 116.0 degrees.
  The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_skymap_all_bn200809654.png
  The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_healpix_all_bn200809654.fit
  The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200809654/quicklook/glg_lc_medres34_bn200809654.gif
  
• GCN Circular #28237
  Aaron Tohuvavohu (U Toronto), James DeLaunay (PSU), Jamie Kennea (PSU) report:
  Swift/BAT did not trigger on GRB 200809B (T0: 2020-08-09 15:41:27 UTC, Fermi/GBM Team GCN 28236).
  The Fermi/GBM notice, distributed at T0+7 seconds triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, arXiv: 2005.01751).
  Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.
  Using the normal BAT imaging technique, we find the location of the GRB with an SNR of 10.4.
  The BAT ground-calculated position is RA, Dec = 15.9406, -73.8459 deg which is

     RA(J2000)  = 01h 3m 45.7s
     Dec(J2000) =  -73d 50’ 45.24”
  

  with an uncertainty of 4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 28.9%.
  This position is consistent with the Fermi GBM localization (GCN 28236).
  XRT and UVOT follow-up has been triggered. Results of follow-up observations will be reported in future circulars.
  GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.
  A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/
• GCN Circular #28238
  S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
  Analysis of AstroSat CZTI data showed the detection of a long GRB 200809B, which was also detected by Fermi GBM (GCN #28236) and Swift/BAT-GUANO (Tohuvavohu A. et al., GCN #28237).
  The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-09 15:41:26.500 UT. The measured peak count rate associated with the burst is 371 +/- 30 cts/s above the background in the combined data of four quadrants, with a total of 706 +/- 7 cts. The local mean background count rate was 537 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 5.44 +/- 0.01 s.
  It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-09 15:41:25.000 UT. The measured peak count rate is 583 +/- 48 cts/s above the background in the combined Veto data of four quadrants, with a total of 785 +/- 19 cts. The local mean background count rate was 1637 +/- 2 cts/s. We measure a T90 of 5.72 +/- 0.45 s from the cumulative Veto light curve.
  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 Circular #28239
  P. A. Evans (U. Leicester) reports on behalf of the Swift team:
  Swift has initiated a ToO observation of the Swift/BAT GRB 200809B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021026
  Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
  Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
  This circular is an official product of the Swift-XRT team.
• GCN Circular #28240
  S. Sugita (AGU), H. Negoro, M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino (Nihon U.), T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, H. Nishida, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.), M. Shidatsu (Ehime U.), N. Kawai, R. Adachi, M. Niwano (Tokyo Tech), S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA), Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), H. Tsunemi (Osaka U.), M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.), Y. Kawakubo (LSU), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), M. Sugizaki (NAOC) report on behalf of the MAXI team:
  The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 15:41:27 UT on 2020 Aug 9. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (15.369 deg, -73.867 deg) = (01 01 28, -73 52 01) (J2000) with a 90% C.L. statistical error of 0.38 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius). The position was consistent with GRB200809B (Fermi GBM: GCN 28236, Swift BAT: 28237). The X-ray flux averaged over the scan was 94 +- 17 mCrab (4.0-10.0keV, 1 sigma error). There was no significant excess flux in the next transit at 8/9 17:14 UT with an upper limit of 20 mCrab.