Gamma-ray Burst 211115A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN NOTICE
  

      
  TITLE:           GCN/MAXI NOTICE
  NOTICE_DATE:     Mon 15 Nov 21 16:52:28 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:      9533572830
  EVENT_RA:        122.87d {+08h 11m 30s} (J2000),
                   123.10d {+08h 12m 25s} (current),
                   122.34d {+08h 09m 23s} (1950)
  EVENT_DEC:       -25.67d {-25d 40' 18"} (J2000),
                   -25.74d {-25d 44' 17"} (current),
                   -25.52d {-25d 31' 18"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      697.0 +- 0.0 [mCrab]
  EVENT_DATE:      19533 TJD;   319 DOY;   21/11/15
  EVENT_TIME:      59488.00 SOD {16:31:28.00} UT
  EVENT_TSCALE:    1day
  EVENT_EBAND:     Low, 2-4 keV
  SUN_POSTN:       231.16d {+15h 24m 39s}  -18.66d {-18d 39' 25"}
  SUN_DIST:         97.22 [deg]
  MOON_POSTN:       13.55d {+00h 54m 13s}   +1.46d {+01d 27' 34"}
  MOON_DIST:       108.20 [deg]
  MOON_ILLUM:      88 [%]
  GAL_COORDS:      244.79,  4.42 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      133.13,-44.31 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.
  

• GCN NOTICE
  

  TITLE:           GCN/MAXI NOTICE
  NOTICE_DATE:     Mon 15 Nov 21 17:20:53 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:      9533572830
  EVENT_RA:        122.98d {+08h 11m 54s} (J2000),
                   123.21d {+08h 12m 50s} (current),
                   122.45d {+08h 09m 48s} (1950)
  EVENT_DEC:       -25.71d {-25d 42' 31"} (J2000),
                   -25.78d {-25d 46' 30"} (current),
                   -25.56d {-25d 33' 29"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      336.0 +- 0.0 [mCrab]
  EVENT_DATE:      19533 TJD;   319 DOY;   21/11/15
  EVENT_TIME:      59488.00 SOD {16:31:28.00} UT
  EVENT_TSCALE:    1day
  EVENT_EBAND:     Low, 2-4 keV
  SUN_POSTN:       231.18d {+15h 24m 44s}  -18.66d {-18d 39' 43"}
  SUN_DIST:         97.13 [deg]
  MOON_POSTN:       13.77d {+00h 55m 05s}   +1.57d {+01d 34' 02"}
  MOON_DIST:       108.15 [deg]
  MOON_ILLUM:      88 [%]
  GAL_COORDS:      244.87,  4.47 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      133.27,-44.32 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient. 
  

• GCN Circular #31082
  M. Serino (AGU), Y. Kawakubo (LSU), H. Negoro, M. Nakajima, K. Kobayashi, K. Asakura, K. Seino (Nihon U.), T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, K. Komachi, H. Hiramatsu, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.), M. Shidatsu (Ehime U.), N. Kawai, M. Niwano, R. Hosokawa (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka, M. Kurihara (JAXA), Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, Y. Goto, R. Uematsu, K. Inaba (Kyoto U.), H. Tsunemi (Osaka U.), M. Yamauchi, Y. Nonaka, T. Sato, R. Hatsuda, R. Fukuoka (Miyazaki U.), T. Kawamuro (UDP/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 2021-11-15T16:31:19 UT. Assuming that the source flux was constant over the transit, we obtain the source position at
  with a statistical 90% C.L. elliptical error region with long and short radii of 0.13 deg and 0.11 deg, respectively. The roll angle of long axis from the north direction is 61.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners:

  (122.347, -24.737) deg = (08 09 23, -24 44 13) (J2000)
  (122.123, -24.889) deg = (08 08 29, -24 53 20) (J2000)
  (123.589, -26.633) deg = (08 14 21, -26 37 58) (J2000)
  (123.815, -26.479) deg = (08 15 15, -26 28 44) (J2000).
  

  The X-ray flux averaged over the scan was 336 +- 35 mCrab (4.0-10.0keV, 1 sigma error). There was no significant excess flux in the previous transit at 14:58 UT with an upper limit of 20 mCrab.
• GCN Circular #31084
  Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
  The long GRB 211115A (MAXI/GSC detection: Serino et al., GCN Circ. 31082; Fermi-GBM trigger #658686687) was detected in ground analysis of the CALET Gamma-ray Burst Monitor (CGBM) data near the MAXI trigger time at 16:31:19 UTC on 15 November 2021. The burst signal was weakly seen by all CGBM detectors.
  The burst light curve shows a single pulse with a duration of ~10 sec.
  The ground processed light curve is available at
  http://cgbm.calet.jp/cgbm_trigger/ground/1321029033/
  The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.