GCN Circular 40676
Subject
GRB 250610B: OHP/T120 optical counterpart candidate
Date
2025-06-10T23:26:37Z (3 days ago)
Edited On
2025-06-11T14:35:11Z (3 days ago)
From
Benjamin Schneider at MIT <bschn@mit.edu>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Benjamin Schneider at MIT <bschn@mit.edu>
Via
Web form
B. Schneider (LAM), A. de Ugarte Postigo (LAM), C. Adami (LAM/Pytheas/AMU), J.P Troncin (Pytheas/OHP), A. Martin-Carrillo (UCD), S. Basa (LAM/OHP/Pytheas/AMU), E. Le Floc'h (CEA/Irfu), K. Siellez (Institute of Astrophysics in Paris / UTas) report on behalf of a larger collaboration:
We observed the field of the GRB 250610B (Saccardi et al., GCN 40671) using the T120cm telescope at Observatoire de Haute-Provence (France). We obtained 30 minutes of exposure in the r-band starting at 20:31:03.29 UT on 2025-06-10 (3.97 hr after the trigger).
In the stacked image, we detected a new source not visible in the Legacy Survey and consistent with the XRT #1 error at RA, Dec 200.1796, +31.1047 which is equivalent to:
RA(J2000) = 13:20:43.11
Dec(J2000) = +31:06:16.8
with an uncertainty of 0.5 arcsec.
The preliminary magnitude derived for that source is:
r = 20.96 +/- 0.15 mag (AB)
The photometric calibration was performed using nearby stars from the SDSS catalog and the magnitude is not corrected for Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence and in particular the students and professors from the summer camp OHP 2025.