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GCN Circular 32310

GRB 220701A: Swift/UVOT Upper Limits
2022-07-01T11:27:13Z (2 years ago)
Samantha Oates at MSSL <>
S. R. Oates (U. Birmingham) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220701A
175 s after the BAT trigger (Evans et al., GCN Circ. 32306).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 32308)
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           175          325          147         >21.0
u_FC               333          583          246         >20.2
white              175         1884          424         >21.6
v                  665         1758          136         >19.2
b                  589         1858          136         >20.2
u                  333         1833          363         >20.5
w1                 714         1808          117         >19.4
w2                 640         1906           55         >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.008 in the direction of the burst
(Schlegel et al. 1998).
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