GCN Circular 43014
Subject
GRB 251203C: Swift/UVOT Upper Limit
Event
Date
2025-12-06T18:22:42Z (2 days ago)
From
N. Klingler at NASA-GSFC/UMBC/CRESST II <noelklingler@gmail.com>
Via
Web form
Swift/UVOT has performed follow-up observations of the field of GRB 251203C, starting 20.3 ks after the SVOM trigger sb25120305 (Brunet et al; GCN Circ. 42976). No source is detected at the position of the optical counterpart (R.A., Dec. = 51.701538, -7.382688) reported by Li et al. (GCN Circ. 42987) and Turpin et al. (GCN Circ. 42988). 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:
Filter T_start(s) T_stop(s) Exp(s) Mag(AB)
u 20269 20514 241 >20.69
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.046 in the direction of the burst (Schlegel et al. 1998).