TITLE:   GCN CIRCULAR
NUMBER:  22610
SUBJECT: IPN Triangulation of GRB 180404C (long)
DATE:    18/04/06 18:02:49 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

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

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

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

A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE team,

and

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

The long-duration GRB 180404C (Marrocchesi et al., GCN Circ. 22607)
was detected by Konus-Wind, Mars-Odyssey (HEND), INTEGRAL (SPI-ACS),
CALET (CGBM), and AGILE (MCAL) at about 78128 s UT (21:42:08).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    92.302 (06h 09m 13s)  +7.811 ( +7d 48' 38")
  Corners:
    94.505 (06h 18m 01s)  +6.262 ( +6d 15' 44")
    90.162 (06h 00m 39s)  +8.179 ( +8d 10' 43")
    90.059 (06h 00m 14s)  +9.822 ( +9d 49' 21")
    94.425 (06h 17m 42s)  +7.688 ( +7d 41' 17")
  ---------------------------------------------
The error box area is 6.37 sq. deg, and its maximum
dimension is 5.66 deg (the minimum one is 80 arcmin).
The Sun distance was 75 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180404_T78131/IPN

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