GCN Circular 39450
Subject
EP250223a: REM NIR upper limit
Date
2025-02-24T11:40:05Z (19 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 EP250223a (Lian et al., GCN 39429; Wang et al., GCN 39448), also detected by Swift/XRT (Kennea et al., GCN 39437) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the J, H, and K bands, started on 2025 February 24 at 01:29:31 UT (i.e. 10.4 hr after the burst), and lasted for about 1 hour.
From preliminary inspection, we do not find any counterpart at the position of the reported optical afterglow (Hauptmann et al., GCN 39436; Levan et al., GCN 39438; Wu et al., GCN 39439; Pérez-Fournon et al., GCN 39440; Izzo & Malesani, GCN 39441; Xin et al., GCN 39445; Guo et al., GCN 39447; An et al., GCN 39449) down to the following 3sigma limit:
H > 17.6 (Vega; calibrated against the 2MASS catalogue),
at a mid-time of 10.85 hours after the trigger.