GRB 210504A: Swift/UVOT Detection
Abstract
The Swift/UVOT began settled observations of the field of GRB 210504A 218 s after the BAT trigger (Beardmore et al., GCN Circ. 29929). A fading source is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 14:49:34.03 = 222.39179 (deg.) Dec (J2000) = -30:32:02.2 = -30.53395 (deg.) with an estimated uncertainty of 0.6 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 218 368 147 19.75 0.19 white 1168 1877 97 20.08 0.31 v 374 739 58 >18.26 b 473 837 58 >19.29 b 1144 1852 97 19.17 0.25 u 448 812 58 >18.89 uvw1 424 788 58 >18.49 uvm2 399 418 20 >17.24 uvw2 523 1040 59 >18.60
- Publication:
-
GRB Coordinates Network
- Pub Date:
- May 2021
- Bibcode:
- 2021GCN.29933....1B