[vsnet-grb-info 25925] GRB 200623A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28025
SUBJECT: GRB 200623A: Swift/UVOT Upper Limits
DATE:    20/06/24 19:15:37 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld at ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and B. Sbarufatti (PSU) report on behalf of the Swift/UVOT team:

The Swift/UVOT began target-of-opportunity observations of the field of GRB 200623A 37910 s after 
the Guano and GBM trigger (Fermi GBM team, GCN Circ. 28011; Debaunay et al., GCN Circ. 28013).

No significant new sources were found at the positions of the XRT candidate sources 1 and 3 
(Tohuvavohu et al., GCN Circ. 28023). XRT source 2 was outside the field of view for all exposures.

Preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. 
Proc. 1358, 373) for the initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white            37910        45836         4299         >22.4

The magnitude in the table is not corrected for the Galactic extinction due to the reddening of 
E(B-V) = 0.012 in the direction of the burst (Schlegel et al. 1998).