TITLE:   GCN CIRCULAR
NUMBER:  30154
SUBJECT: IPN triangulation of GRB 210606B
DATE:    21/06/08 19:34:53 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak,
and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,

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

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,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The bright, long-duration 210606B
(GECAM detection: Cai et al., GCN Circ. 30138;
BALROG localization: Kunzweiler et al., GCN Circ. 30139;
AGILE detection: Ursi et al., GCN Circ. 30142;
Fermi-GBM detection: The Fermi GBM team, GCN Circ. 30147)
was detected by Fermi (GBM trigger 644712030), Konus-Wind,
INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), GECAM, AGILE (SA, MCAL, and AC)
and Swift (BAT) at about 81625 s UT (22:40:25)
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    87.986 (05h 51m 57s) -16.689 (-16d 41' 19")
  Corners:
    86.597 (05h 46m 23s) -15.596 (-15d 35' 45")
    89.249 (05h 57m 00s) -17.675 (-17d 40' 30")
    89.394 (05h 57m 35s) -17.719 (-17d 43' 07")
    86.742 (05h 46m 58s) -15.651 (-15d 39' 05")
  ---------------------------------------------
The error box area is 588 sq. arcmin, and its maximum
dimension is 3.4 deg (the minimum one is 3 arcmin).
The Sun distance was 40 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi RoboBA and BALROG localizations (GCN Circ. 30147 and 30139).

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB210606_T81665/IPN/

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