[vsnet-grb-info 26367] IPN triangulation of GRB 200920B (short)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28467
SUBJECT: IPN triangulation of GRB 200920B (short)
DATE:    20/09/21 20:34:34 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia at mail.ioffe.ru>

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and A. Ursi, F. Verrecchia, M. Tavani, N. Parmiggiani, C. Pittori,
A. Bulgarelli, on behalf of the AGILE team, report:

The short-duration GRB 200920B
(AGILE/MCAL detection: Ursi et al., GCN Circ. 28464)
has been detected by Fermi (GBM trigger 622324624), Konus-Wind,
INTEGRAL (SPI-ACS), and AGILE (MCAL), so far,
at about 71815 s UT (19:56:55).

We have triangulated it to a Konus-GBM annulus centered at
RA(2000)=157.135 deg (10h 28m 32s)  Dec(2000)=+10.976 deg (+10d 58' 33"),
whose radius is 4.834 +/- 1.787 deg (3 sigma),
to a Konus-INTEGRAL annulus centered at
RA(2000)=154.111 deg (10h 16m 27s)  Dec(2000)=+8.715 deg (+8d 42' 54"),
whose radius is 7.120 +/- 1.815 deg (3 sigma), and
to a GBM-INTEGRAL annulus centered at
RA(2000)=77.242 deg (05h 08m 58s)  Dec(2000)=-35.743 deg (-35d 44' 36"),
whose radius is 90.000 +/- 4.602 deg (3 sigma).

The preliminary, 3 sigma error box is:
 ---------------------------------------------
  RA(2000), deg       Dec(2000), deg
 ---------------------------------------------
 Center:
  160.5209           +13.4321
 Corners:
  161.4146           +14.0653
  155.8758           +17.4839
  150.6190           +12.7611
  155.8316           +13.7440
  159.6319           +12.7958
  159.4728           +8.9807
  157.1525           +4.3546
  163.1097           +7.9563
 ---------------------------------------------
The error box area is 51.5 sq. deg, and its maximum
dimension is 13.2 deg (the minimum one is 2.1 deg).
The Sun distance was 123 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200920_T71814/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.