GCN Circular 17521
Subject
GRB 150301A: Swift/UVOT Upper Limits
Date
2015-03-02T00:59:47Z (9 years ago)
From
Lea Hagen at PSU <lea.zernow.hagen@gmail.com>
L. M. Z. Hagen (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150301A
66 s after the BAT trigger (Lien et al., GCN Circ. 17510).
No optical afterglow consistent with the XRT position (Lien et al.
GCN Circ. 17510) or GROND candidates (Tanga et al. GCN Circ. 17513)
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
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 66 4931 306 >21.08
v 5143 5343 196 >19.40
b 4526 10879 750 >21.16
u 4321 5926 362 >20.08
uvw1 5553 5752 196 >19.61
uvm2 5347 5547 196 >19.40
uvw2 4937 5137 196 >19.82
The magnitudes in the table are not corrected for the substantial Galactic
extinction due to the reddening of E(B-V) = 3.84 in the direction of the
burst (Schlegel et al. 1998). We note that the photometry is likely
affected by a nearby bright foreground star.