GCN Circular 17977
Subject
GRB 150627A: Swift/UVOT Detection
Date
2015-06-28T09:26:32Z (9 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
Paul Kuin (MSSL-UCL), Marissa McCauley (PSU) and Daniele Malesani
(DARK/NBI) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of the Fermi GRB
150627A 33622 s after the LAT trigger (Arimoto et al., GCN Circ. 17971;
Yu et al., GCN Circ. 17975).
An optical object consistent with the XRT position (Gompertz et al., GCN
Circ. 17976) is detected at RA, Dec = 117.47108, -51.489417 deg (J2000),
which is equivalent to:
RA (J2000): 07:49:53.06
Dec(J2000): -51:29:21.9
with an uncertainty of 1".
Preliminary detections 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 33963 34289 335 19.11+/-0.10
white 39860 40112 248 19.55+/-0.17
white 45659 45863 204 19.28+/-0.14
v 34304 34601 298 19.02+/-0.32
v 40117 40346 225 18.98+/-0.36
u 33622 38243 577 18.90+/-0.10
u 43668 45654 966 19.00+/-0.11
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.32 in the direction of the
burst (Schlegel et al. 1998).
While no optical variability can be securely inferred from the UVOT
photometry, the source is not visible in the DSS survey, and brighter
than its limit, which suggests it to be the optical afterglow of GRB
150627A.