GCN Circular 40690
Subject
EP250610A: Swift/UVOT Upper limits
Date
2025-06-11T14:39:47Z (2 days ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
Via
Web form
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of EP250610A 3 ks after the EP trigger (Zhang et al., GCN Circ. 40660). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 40662) is seen in the initial UVOT exposures.
Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u 3087 9399 2103 >21.44
u 35617 41300 1846 >21.33
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).