Gamma-ray Burst 201021B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/MAXI NOTICE
  NOTICE_DATE:     Wed 21 Oct 20 17:27:08 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:      9143544224  
  EVENT_RA:          3.48d {+00h 13m 55s} (J2000), 
                     3.73d {+00h 14m 55s} (current),
                     2.87d {+00h 11m 29s} (1950)
  EVENT_DEC:       -63.55d {-63d 33' 13"} (J2000),
                   -63.44d {-63d 26' 17"} (current),
                   -63.83d {-63d 49' 54"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      523.0 +- 0.0 [mCrab] 
  EVENT_DATE:      19143 TJD;   295 DOY;   20/10/21
  EVENT_TIME:      58746.00 SOD {16:19:06.00} UT
  EVENT_TSCALE:    1s
  EVENT_EBAND:     Low, 2-4 keV  
  SUN_POSTN:       206.75d {+13h 46m 59s}  -11.04d {-11d 02' 20"}
  SUN_DIST:        103.45 [deg]
  MOON_POSTN:      276.74d {+18h 26m 58s}  -24.48d {-24d 28' 54"}
  MOON_DIST:        66.92 [deg]  
  MOON_ILLUM:      31 [%]
  GAL_COORDS:      309.87,-53.07 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      323.30,-56.33 [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:     Wed 21 Oct 20 17:58:49 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:      9143544224  
  EVENT_RA:          3.57d {+00h 14m 16s} (J2000), 
                     3.82d {+00h 15m 16s} (current),
                     2.96d {+00h 11m 50s} (1950)
  EVENT_DEC:       -63.49d {-63d 29' 30"} (J2000),
                   -63.38d {-63d 22' 34"} (current),
                   -63.77d {-63d 46' 10"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      208.0 +- 0.0 [mCrab] 
  EVENT_DATE:      19143 TJD;   295 DOY;   20/10/21
  EVENT_TIME:      58746.00 SOD {16:19:06.00} UT
  EVENT_TSCALE:    1s
  EVENT_EBAND:     Low, 2-4 keV  
  SUN_POSTN:       206.77d {+13h 47m 04s}  -11.05d {-11d 02' 48"}
  SUN_DIST:        103.52 [deg]  
  MOON_POSTN:      277.08d {+18h 28m 19s}  -24.49d {-24d 29' 38"}
  MOON_DIST:        66.81 [deg]  
  MOON_ILLUM:      31 [%]
  GAL_COORDS:      309.83,-53.14 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      323.43,-56.31 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.
  

• GCN Circular #28726
  S. Nakahira (JAXA), M. Serino (AGU), Y. Kawakubo (LSU), H. Negoro, M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino (Nihon U.),  T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Nishida, K. Komachi, A. Yoshida (AGU),  Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.),  M. Shidatsu (Ehime U.), N. Kawai, R. Adachi, M. Niwano (Tokyo Tech),  Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA),  Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, U. Goto, R. Uematsu (Kyoto U.),  H. Tsunemi (Osaka U.),  M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.),  T. Kawamuro (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 2020-10-21T16:18:55UT . Assuming that the source flux was constant over the transit, we obtain the source position at

  (R.A., Dec) = (3.592 deg, -63.535 deg) = (00 14 22, -63 32 05) (J2000)
  

  with a 90% C.L. statistical error of 0.24 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 212 +- 25 mCrab (4.0-10.0keV, 1 sigma error). There was no significant excess flux in the previous transit at UT 14:46  and in the next transit at 17:51 UT with an upper limit of 20 mCrab for each.