Gamma-ray Burst 210430A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #29914
  B. Sbarufatti (PSU), A. Y. Lien (GSFC/UMBC) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
  At 10:42:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210430A (trigger= 1046014). Swift did not slew immediately due to an observing constraint. The BAT on-board calculated location is RA, Dec 57.178, +45.074 which is

     RA(J2000) = 03h 48m 43s
     Dec(J2000) = +45d 03' 31"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). With the currently available data from ~T-50 s to ~T+30 s, the BAT light curve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~2 sec after the trigger.
  The BAT position is sun-constrained for Swift until July 8 2021, there will be no XRT or UVOT followup before this time.
  Burst Advocate for this burst is B. Sbarufatti (bxs60 AT psu.edu). 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/)
• GCN Circular #29918
  H. A. Krimm (NSF), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (PSU), 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 210430A (trigger #1046014) (Sbarufatti et al., GCN Circ. 29914). The BAT ground-calculated position is RA, Dec = 57.185, 45.080 deg which is

     RA(J2000)  =  03h 48m 44.3s
     Dec(J2000) = +45d 04' 46.9"
  

  with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 25%.
  The mask-weighted light curve shows a single-peaked structure that starts at ~T-3 s, peaks at ~T+2 s, and ends at ~T+15 s. T90 (15-350 keV) is 11.53 +- 2.83 sec (estimated error including systematics).
  The time-averaged spectrum from T-2.72 to T+14.60 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.21. The fluence in the 15-150 keV band is 9.9 +- 1.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+1.14 sec in the 15-150 keV band is 1.9 +- 0.4 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/1046014/BA/
• GCN Circular #29921
  T.-R Sun, Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, M. A. Castro Tirado, F. Rendon (IAA-CSIC), C. Perez del Pulgar, A. Castellon and A. J. Reina (Univ. de Malaga) on behalf of a larger collaboration, report:
  Following the detection of GRB 210430A by Swift (Moss et al. GCNC 29918), we triggered the 0.3m BOOTES-1B robotic telescope at the BOOTES-1 astronomical station at ESAt/INTA-CEDEA in Mazag¨Žn (Huelva, Spain), gathering images starting on Apr 30, 20:30 UT, about 9.8 hours after the onset of the GRB. After co-adding the corresponding images, nothing is found within the GRB 210430A error box down to 18.4 limiting magnitude, after calibrating the image with G mag in the GAIA DR2 catalogue.
  We thank the staff at INTA-CEDEA for their excellent support.