TITLE:   GCN CIRCULAR
NUMBER:  36891
SUBJECT: GRB 240715A: Swift/UVOT observations of the XRT sources.
DATE:    24/07/16 17:17:40 GMT
FROM:    Samantha Oates at University of Birmingham <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (Lancaster U.) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240715A
36 ks after the Fermi/GBM trigger (Fermi GBM team, GCN Circ. 36866).

The UVOT exposures include the positions of XRT sources 1 and 2, but
XRT source 3 is outside of the UVOT field of view (D'Elia et al., GCN 36890).
In the UVOT exposures, optical sources are found consistent with
XRT source 1 and 2. These sources are also observed in the DSS.

Preliminary magnitudes using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the two XRT sources are:

     Source          Filter     T_start(s)  T_stop(s)    Exp(s)       Mag
XRT source 1    white         36242     54326        4613     20.1+\-0.1
XRT source 2    white         36242     54326        4613     21.8+\-0.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).