GCN Circular 42667
Subject
GRB 251112A: Swift/UVOT Upper Limits
Event
Date
2025-11-13T14:23:39Z (a day ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
Via
email
A.A. Breeveld (UCL-MSSL) and A. Mei (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 251112A 304 s after the BAT trigger (Mei et al., GCN Circ. 42656).
No optical afterglow consistent with the XRT position (Lanava et al., GCN Circ. 42665) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u_FC 304 553 246 >19.9
white 856 944 86 >20.0
uvw1 683 697 14 >17.2
uvm2 658 849 39 >17.6
uvw2 609 801 39 >18.0
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.158 in the direction of the burst (Schlegel et al. 1998).