Gamma-ray Burst 200228A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Fri 28 Feb 20 06:58:58 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      44
  TRIGGER_NUM:     604565918
  GRB_RA:          304.133d {+20h 16m 32s} (J2000),
                   304.532d {+20h 18m 08s} (current),
                   303.141d {+20h 12m 34s} (1950)
  GRB_DEC:         -56.550d {-56d 32' 59"} (J2000),
                   -56.487d {-56d 29' 11"} (current),
                   -56.704d {-56d 42' 14"} (1950)
  GRB_ERROR:       4.00 [deg radius, statistical plus systematic]
  GRB_INTEN:       1399 [cnts/sec]
  DATA_SIGNIF:     49.00 [sigma]
  INTEG_TIME:      0.512 [sec]
  GRB_DATE:        18907 TJD;    59 DOY;   20/02/28
  GRB_TIME:        25113.81 SOD {06:58:33.81} UT
  GRB_PHI:          60.00 [deg]
  GRB_THETA:        30.00 [deg]
  DATA_TIME_SCALE: 0.5120 [sec]
  HARD_RATIO:      0.63
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      96%  GRB
  2nd_MOST_LIKELY:   3%  Generic Transient
  DETECTORS:       0,1,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:       340.74d {+22h 42m 57s}   -8.14d {-08d 08' 16"}
  SUN_DIST:         56.01 [deg]   Sun_angle= 2.4 [hr] (West of Sun)
  MOON_POSTN:       29.30d {+01h 57m 11s}   +7.04d {+07d 02' 24"}
  MOON_DIST:        92.99 [deg]
  MOON_ILLUM:      18 [%]
  GAL_COORDS:      341.19,-33.95 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      292.40,-35.73 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_lc_medres34_bn200228291.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 123.57,-24.93 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Fri 28 Feb 20 06:59:07 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      58
  TRIGGER_NUM:     604565918
  GRB_RA:          317.683d {+21h 10m 44s} (J2000),
                   318.063d {+21h 12m 15s} (current),
                   316.737d {+21h 06m 57s} (1950)
  GRB_DEC:         -58.167d {-58d 10' 00"} (J2000),
                   -58.083d {-58d 05' 00"} (current),
                   -58.371d {-58d 22' 15"} (1950)
  GRB_ERROR:       4.13 [deg radius, statistical plus systematic]
  GRB_INTEN:       1183 [cnts/sec]
  DATA_SIGNIF:     84.90 [sigma]
  INTEG_TIME:      2.048 [sec]
  GRB_DATE:        18907 TJD;    59 DOY;   20/02/28
  GRB_TIME:        25113.81 SOD {06:58:33.81} UT
  GRB_PHI:          48.00 [deg]
  GRB_THETA:        25.00 [deg]
  DATA_TIME_SCALE: 2.0480 [sec]
  HARD_RATIO:      0.77
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      97%  GRB
  2nd_MOST_LIKELY:   2%  Generic Transient
  DETECTORS:       0,1,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:       340.74d {+22h 42m 57s}   -8.14d {-08d 08' 16"}
  SUN_DIST:         52.91 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
  MOON_POSTN:       29.30d {+01h 57m 11s}   +7.04d {+07d 02' 25"}
  MOON_DIST:        86.29 [deg]
  MOON_ILLUM:      18 [%]
  GAL_COORDS:      337.91,-40.95 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      300.44,-39.66 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_lc_medres34_bn200228291.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 123.57,-24.93 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Fri 28 Feb 20 06:59:15 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      57
  TRIGGER_NUM:     604565918
  GRB_RA:          326.860d {+21h 47m 26s} (J2000),
                   327.188d {+21h 48m 45s} (current),
                   326.042d {+21h 44m 10s} (1950)
  GRB_DEC:         -48.960d {-48d 57' 35"} (J2000),
                   -48.866d {-48d 51' 56"} (current),
                   -49.192d {-49d 11' 30"} (1950)
  GRB_ERROR:       5.19 [deg radius, statistical only]
  DATA_SIGNIF:     87.70 [sigma]
  DATA_INTERVAL:   2.048 [sec]
  GRB_DATE:        18907 TJD;    59 DOY;   20/02/28
  GRB_TIME:        25113.81 SOD {06:58:33.81} UT
  GRB_PHI:          29.00 [deg]
  GRB_THETA:        31.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   4173 (Gnd S/W Version number)
  SUN_POSTN:       340.74d {+22h 42m 57s}   -8.14d {-08d 08' 16"}
  SUN_DIST:         42.29 [deg]   Sun_angle= 0.9 [hr] (West of Sun)
  MOON_POSTN:       29.30d {+01h 57m 12s}   +7.04d {+07d 02' 27"}
  MOON_DIST:        77.70 [deg]
  MOON_ILLUM:      18 [%]
  GAL_COORDS:      348.48,-48.58 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      311.14,-33.31 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_lc_medres34_bn200228291.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_604565918.fits
  COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
  COMMENTS:        In the LAT Field-of-view.  
  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:     Fri 28 Feb 20 07:07:56 UT
  NOTICE_TYPE:     Fermi-GBM Final Position
  RECORD_NUM:      0
  TRIGGER_NUM:     604565918
  GRB_RA:          328.010d {+21h 52m 02s} (J2000),
                   328.330d {+21h 53m 19s} (current),
                   327.212d {+21h 48m 51s} (1950)
  GRB_DEC:         -46.450d {-46d 27' 00"} (J2000),
                   -46.355d {-46d 21' 16"} (current),
                   -46.685d {-46d 41' 05"} (1950)
  GRB_ERROR:       1.51 [deg radius, statistical only]
  GRB_DATE:        18907 TJD;    59 DOY;   20/02/28
  GRB_TIME:        25113.81 SOD {06:58:33.81} UT
  GRB_PHI:          26.00 [deg]
  GRB_THETA:        33.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   41731 (Gnd S/W Version number)
  SUN_POSTN:       340.74d {+22h 42m 58s}   -8.14d {-08d 08' 08"}
  SUN_DIST:         39.67 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
  MOON_POSTN:       29.37d {+01h 57m 28s}   +7.07d {+07d 04' 05"}
  MOON_DIST:        75.96 [deg]
  MOON_ILLUM:      18 [%]
  GAL_COORDS:      351.94,-49.93 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      313.16,-31.32 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_lc_medres34_bn200228291.gif
  LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_locplot_all_bn200228291.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:        In the LAT Field-of-view.  
  COMMENTS:        This is likely a Long GRB.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=8522).  
  

• GCN Circular #27247
  The Fermi GBM team reports the detection of a likely LONG GRB
  At 06:58:33 UT on 28 Feb 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200228A (trigger 604565918.806272 / 200228291).
  The on-ground calculated location, using the Fermi GBM trigger data, is RA = 328.0, Dec = -46.5 (J2000 degrees, equivalent to J2000 21h 52m, -46d 30'), with a statistical uncertainty of 1.5 degrees.
  The angle from the Fermi LAT boresight is 33.0 degrees.
  The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_skymap_all_bn200228291.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/bn200228291/quicklook/glg_healpix_all_bn200228291.fit
  The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200228291/quicklook/glg_lc_medres34_bn200228291.gif
• GCN Circular #27248
  F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
  The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 604565918 at 06:58:33 on 28 Feb. 2020 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60).
  The best-fit position (1 sigma statistical errors) is:

  RA(2000.0) = 332.9+/-0.9 deg
  Decl.(2000.0) = -39.9+/-1.0 deg
  

  We estimate an additional systematic error of 1 deg.
  Further details are available at: https://grb.mpe.mpg.de/grb/GRB200228291/
  The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB200228291/healpix
  The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB200228291/json
• GCN Circular #27252
  V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department),
  R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
  H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
  R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
  D. Buckley (South African Astronomical Observatory),
  O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
  A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
  V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
  MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB200228.29 (trigger No 604565918,21h 52m 02.40s , -46d 27m 00.0s, R=1.51) errorbox 5750 sec after trigger time at 2020-02-28 08:34:23 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 81 deg. The sun altitude is -23.1 deg.
  The galactic latitude b = -51 deg., longitude l = 352 deg.
  Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1300070
  We obtain a following upper limits.

  Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
  _________|_____________________|_____________________|____________________________________|_____|_______|_______|________
  
      5840 | 2020-02-28 08:34:23 |         MASTER-OAFA | (21h 50m 46.37s , -46d 04m 53.9s) |   C |   180 | 17.4 |        
      6054 | 2020-02-28 08:37:58 |         MASTER-OAFA | (21h 50m 58.67s , -46d 06m 26.5s) |   C |   180 | 18.1 |        
      7542 | 2020-02-28 09:02:45 |         MASTER-OAFA | (21h 47m 01.75s , -47d 53m 08.8s) |   C |   180 | 18.5 |        
      7753 | 2020-02-28 09:06:16 |         MASTER-OAFA | (21h 46m 54.08s , -47d 53m 30.7s) |   C |   180 | 18.9 |        
      7964 | 2020-02-28 09:09:48 |         MASTER-OAFA | (21h 58m 56.72s , -46d 34m 38.3s) |   C |   180 | 18.6 |        
      8175 | 2020-02-28 09:13:19 |         MASTER-OAFA | (21h 59m 03.86s , -46d 35m 37.3s) |   C |   180 | 18.6 |        
  

  Filter C is a clear (unfiltred) band.
  The observation and reduction will continue. The message may be cited.
• GCN Circular #27259
  Aaron Tohuvavohu (U Toronto), James DeLaunay (PSU), and Jamie Kennea (PSU) report:
  Swift/BAT did not trigger on GRB 200228A, likely due to a slew.
  The Fermi/GBM Flight-Position notice, distributed at T0+23 seconds, from the Fermi/GBM detected GRB 200228A (GCN. 27247) triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, in prep).
  The 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.
  Upon trigger by the Fermi 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 GRB 200228A.
  All the requested event mode data was delivered to the ground.
  In a ground analysis of the data, using the normal BAT imaging technique, we detect GRB 200228A with a SNR of 40.
  The BAT ground-calculated position is RA, Dec = 333.8928, -42.9443 deg which is

     RA(J2000)  = 333d 53m 34.08s
     Dec(J2000) =  -42d 56' 39.48"
  

  with an uncertainty of 3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 34%.
  This arcminute location is consistent with the localization region distributed by the Fermi/GBM team (GCN. 27247).
  No XRT or UVOT follow-up will take place due to the source's proximity to the sun (0.5 hours). We encourage follow-up from instruments capable of observing near the sun.
• GCN Circular #27260
  E. Bissaldi (Politecnico and INFN Bari) reports on behalf of the Fermi GBM Team:
  "At 06:58:33.81 UT on 28 February 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200228A (trigger 604565918 / 200228291), as reported by the Fermi GBM Final Real-time Localization (GCN 27247). The GBM localization is consistent with the Swift GUANO localization (Tohuvavohu et al. 2020, GCN 27259).
  The angle from the Fermi LAT boresight at the GBM trigger time is 33 degrees.
  The GBM light curve consists of a single bright peak with a duration (T90) of about 4 s (50-300 keV). The time-averaged spectrum from T0 to T0+4 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.61 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 165 +/- 5 keV.
  The event fluence (10-1000 keV) in this time interval is (6.44 +/- 0.13)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.0 s in the 10-1000 keV band is 20.4 +/- 0.4 ph/s/cm^2.
  A Band function fits the spectrum equally well with Epeak= 153 +/- 7 keV, alpha = -0.54 +/- 0.05 and beta = -2.85 +/- 0.23.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
  For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
• GCN Circular #27302
  S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
  Analysis of AstroSat CZTI data showed the detection of the long GRB 200228A, which was also detected by Fermi GBM Final Real-time Localization (GCN #27247), BALROG (Kunzweiler F. et al., GCN #27248) and Swift/BAT (Tohuvavohu A. et al., GRB #27259).
  The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-02-28 06:58:33.01 UT. The measured peak count rate associated with the burst is 537 +/- 33.1 cts/s above the background in the combined data of four quadrants, with a total of 1496 +/- 9.8 cts. The local mean background count rate was 551 +/- 1.4 cts/s. Using cumulative rates, we measure a T90 of 4.8 +/- 0.02 s.
  It was also clearly detected in the CsI anticoincidence (Veto) detector 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.