Gamma-ray Burst 260122B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Thu 22 Jan 26 23:14:50 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     1443066,   Seg_Num: 0
  GRB_RA:          336.079d {+22h 24m 19s} (J2000),
                   336.510d {+22h 26m 02s} (current),
                   335.245d {+22h 20m 59s} (1950)
  GRB_DEC:         -59.167d {-59d 10' 02"} (J2000),
                   -59.035d {-59d 02' 04"} (current),
                   -59.421d {-59d 25' 15"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       17766 [cnts]    Image_Peak=411 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   300     E_range: 25-100 keV
  BKG_INTEN:       168105 [cnts]
  BKG_TIME:        83530.90 SOD {23:12:10.90} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        21062 TJD;    22 DOY;   26/01/22
  GRB_TIME:        83590.04 SOD {23:13:10.04} UT
  GRB_PHI:         -122.94 [deg]
  GRB_THETA:        28.19 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     11.44 [sigma]
  IMAGE_SIGNIF:    9.35 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +2  +0 -100  +0 -70  +0 
  SUN_POSTN:       305.24d {+20h 20m 57s}  -19.50d {-19d 29' 46"}
  SUN_DIST:         45.51 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
  MOON_POSTN:      352.29d {+23h 29m 10s}   -2.10d {-02d 05' 51"}
  MOON_DIST:        58.25 [deg]
  MOON_ILLUM:      17 [%]
  GAL_COORDS:      330.94,-49.19 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      311.36,-44.84 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
  COMMENTS:        probably due to it occurring during a Malindi downlink session.  
  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 = 321.91,-13.36 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN Circular #43501
  V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
  MASTER-SAAO robotic telescope [1] located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB260122.97 (trigger No 1443066,22h 24m 18.96s , -59d 10m 01.2s, R=0.05) errorbox 84 sec after notice time and 187 sec after trigger time at 2026-01-22 23:16:17 UT, with upper limit up to 15.9 mag. The observations began at zenith distance = 87 deg. The sun altitude is -38.0 deg.
  The galactic latitude b = -50 deg., longitude l = 331 deg.
  Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3112208
  We obtain a following upper limits.

  Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
  _________|_____________________|_____|_______|______|________
  
       207 |         MASTER-SAAO |  P\ |    40 | 15.9 |        
  

  The observation and reduction will continue. The message may be cited.
  [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http:// www.pereplet.ru/lipunov/625.html
• GCN Circular #43502
  A. Mei (INAF-OAB), R. Brivio (INAF-OAB), R. Gupta (NASA GSFC), A. Y. Lien (U Tampa) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
  At 23:13:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 260122B (trigger=1443066). Swift did not slew immediately to the burst due to observing constraint. The BAT on-board calculated location is RA, Dec 336.079, -59.167 which is

     RA(J2000) = 22h 24m 19s
     Dec(J2000) = -59d 10' 02"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 15 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger. We note that the burst occurred during the high background interval near the SAA. Therefore, at this moment we cannot completely rule out the possibility that the event is due to background fluctuation. However, given that the image significance is 9.35 sigma, we believe this is likely a real burst. Further ground data is required to determine the nature of the burst.
  Due to a Sun observing constraint, Swift cannot slew to the BAT position until 2026 February 16. There will thus be no XRT or UVOT data for this trigger.
  Burst Advocate for this burst is A. Mei (alessio.mei AT 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/)
• GCN Circular #43507
  D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), A. Mei (INAF-OAB), M. J. Moss (GSFC), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team):
  Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 260122B (trigger #1443066) (Mei et al., GCN Circ. 43502). The ground analysis confirms that this event is indeed a GRB and not due to background fluctuations (Mei et al., GCN Circ. 43502). The BAT ground-calculated position is RA, Dec = 336.096, -59.176 deg which is

     RA(J2000)  =  22h 24m 22.9s
     Dec(J2000) = -59d 10' 32.1"
  

  with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 57%.
  The mask-weighted light curve shows a single-pulse structure that starts ~T-1 s, peaks at ~T+9 s, and ends at ~T+20 s. T90 (15-350 keV) is 16.59 +- 3.89 sec (estimated error including systematics).
  The time-averaged spectrum from T+0.23 to T+19.51 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.34 +- 0.17. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+8.46 sec in the 15-150 keV band is 1.6 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
  The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1443066