GCN Circular 40395
Subject
EP250508a: REM optical/NIR observations
Date
2025-05-08T10:22:35Z (2 days ago)
From
Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it>
Via
Web form
R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team:
We observed the field of GRB EP250508a detected by EP/WXT (Liang et al., GCN 40390) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, J, H, and K bands, started on 2025 May 08 at 06:12:51 UT (i.e. about 9 minutes after the burst), and lasted for about 2 hours.
From preliminary inspection, we do not detect any possible counterpart inside the EP/FXT error circle down to the following 3sigma limits:
r > 19.2 (AB; calibrated against the Pan-STARRS catalogue),
at a mid-time of 51 minutes after the trigger;
H > 16.0 (Vega; calibrated against the 2MASS catalogue),
at a mid-time of 57 minutes after the trigger.