GCN Circular 29764
Subject
GRB 210402A: Swift/UVOT Upper Limits
Date
2021-04-05T23:52:02Z (3 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 210402A: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and K. L. Page (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210402A
73 s after the BAT trigger (Page et al., GCN Circ. 29743).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 29750)
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
white_FC 163 313 147 >20.8
u_FC 321 571 246 >20.3
white 163 1718 411 >21.4
v 653 5581 229 >19.6
b 578 1694 117 >20.2
u 321 1669 304 >20.2
w1 1108 1644 78 >19.2
w2 1207 1227 19 >18.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.018 in the direction of the burst
(Schlegel et al. 1998).