Gamma-ray Burst 240603B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 03 Jun 24 06:57:59 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     1232755,   Seg_Num: 0
  GRB_RA:           36.054d {+02h 24m 13s} (J2000),
                    36.268d {+02h 25m 04s} (current),
                    35.615d {+02h 22m 28s} (1950)
  GRB_DEC:         -50.944d {-50d 56' 38"} (J2000),
                   -50.835d {-50d 50' 03"} (current),
                   -51.170d {-51d 10' 11"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       1347 [cnts]    Image_Peak=83 [image_cnts]
  TRIGGER_DUR:     0.512 [sec] 
  TRIGGER_INDEX:   201     E_range: 15-50 keV
  BKG_INTEN:       19116 [cnts]
  BKG_TIME:        25046.43 SOD {06:57:26.43} UT
  BKG_DUR:         8 [sec]
  GRB_DATE:        20464 TJD;   155 DOY;   24/06/03
  GRB_TIME:        25063.65 SOD {06:57:43.65} UT
  GRB_PHI:         -145.38 [deg]
  GRB_THETA:        27.69 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     14.42 [sigma]
  IMAGE_SIGNIF:    7.01 [sigma]
  MERIT_PARAMS:     +1  +0  +0  -1  +1  -3  +0  +0 -17  +0 
  SUN_POSTN:        71.79d {+04h 47m 09s}  +22.38d {+22d 22' 46"}
  SUN_DIST:         79.62 [deg]   Sun_angle= 2.4 [hr] (West of Sun)
  MOON_POSTN:       27.92d {+01h 51m 40s}  +13.14d {+13d 08' 31"}
  MOON_DIST:        64.39 [deg]
  MOON_ILLUM:      13 [%]
  GAL_COORDS:      272.77,-60.40 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        3.52,-59.31 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 138.75,-12.02 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 03 Jun 24 07:01:31 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     1232755,   Seg_Num: 0
  GRB_RA:           36.054d {+02h 24m 13s} (J2000),
                    36.268d {+02h 25m 04s} (current),
                    35.615d {+02h 22m 28s} (1950)
  GRB_DEC:         -50.944d {-50d 56' 38"} (J2000),
                   -50.835d {-50d 50' 03"} (current),
                   -51.170d {-51d 10' 11"} (1950)
  GRB_DATE:        20464 TJD;   155 DOY;   24/06/03
  GRB_TIME:        25063.65 SOD {06:57:43.65} UT
  TRIGGER_INDEX:   201
  GRB_PHI:         -145.38 [deg]
  GRB_THETA:        27.69 [deg]
  DELTA_TIME:      38.00 [sec]
  TRIGGER_DUR:     0.512 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     14.42 [sigma]
  IMAGE_SIGNIF:    7.01 [sigma]
  LC_URL:          sw01232755000msb.lc
  SUN_POSTN:        71.79d {+04h 47m 09s}  +22.38d {+22d 22' 47"}
  SUN_DIST:         79.62 [deg]   Sun_angle= 2.4 [hr] (West of Sun)
  MOON_POSTN:       27.95d {+01h 51m 48s}  +13.16d {+13d 09' 26"}
  MOON_DIST:        64.40 [deg]
  MOON_ILLUM:      13 [%]
  GAL_COORDS:      272.77,-60.40 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        3.52,-59.31 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Lightcurve.  
  COMMENTS:           
  COMMENTS:        The next comments were copied from the BAT_POS Notice:  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 138.75,-12.02 [deg].  
  

  
• GCN Circular #36604
  A. P. Beardmore (U Leicester), A. Y. Lien (U Tampa) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team:
  At 06:57:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located on a possible GRB 240603B (trigger=1232755). Swift did not slew immediately to the location. The BAT on-board calculated location is RA, Dec 36.054, -50.944 which is

     RA(J2000) = 02h 24m 13s
     Dec(J2000) = -50d 56' 38"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve did not show any significant structures, despite the light curve fluctuated greatly from ~4000 ct/s to ~10000 ct/s. Also, the source was detected with marginal significance (7.0 sigma) in the image, but the source is no longer detected in the scaled map from ground analysis. Therefore, the trigger may be due to a noisy detector. However, further ground data and XRT/UVOT observation is required to confirm the nature of the trigger.
  Due to an observing constraint, Swift will not slew until T0+54.8 minutes. There will be no XRT or UVOT data until this time.
  Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.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/)