GCN Circular 37919
Subject
GRB 241025A: Swift/UVOT Detection
Date
2024-10-28T01:28:28Z (2 months ago)
From
noelklin@umbc.edu
Via
Web form
N. J. Klingler (GSFC/UMBC/CRESTII) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 241025A
126 s after the BAT trigger (Ambrosi et al., GCN Circ. 37859).
A source consistent with the XRT position (Evans et al.; GCN Circ. 37868)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 22:14:36.83 = 333.65346 (deg.)
Dec (J2000) = +83:34:32.2 = 83.57562 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 126 275 147 17.55 +/- 0.04
v 671 5229 274 >19.4
b 595 1347 78 >20.2
u 339 1322 304 >20.5
w1 722 5483 101 >21.0
m2 5234 5434 197 >20.2
w2 1030 1050 19 >19.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.249 in the direction of the burst
(Schlegel et al. 1998).