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GCN Circular 28025

GRB 200623A: Swift/UVOT Upper Limits
2020-06-24T19:15:37Z (4 years ago)
Alice Breeveld at MSSL-UCL <>
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).
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