GCN Circular 18270
Subject
GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
Event
Date
2015-09-10T16:11:49Z (10 years ago)
From
Marissa McCaule at PSU <marissamc@swift.psu.edu>
L. M. McCauley (PSU) and C. Pagani (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150910A
154 s after the BAT trigger (Pagani et al., GCN Circ. 18264).
A source consistent with the XRT position
(Pagani et al. GCN Circ. 18264)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 00:22:40.11 = 5.66713 (deg.)
Dec (J2000) = +33:28:21.9 = 33.47274 (deg.)
with an estimated uncertainty of 0.58 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) show a very rapid and steep
rise in the luminosity of the afterglow over the first 1 ks of observation.
Further investigation is strongly encouraged.
Preliminary detections for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 153 303 147 19.90
white 156 303 144 19.93
white 592 612 19 17.09
white 765 785 19 16.67
white 866 1016 147 16.30
v 135 145 9 >17.23
v 642 662 19 16.64
v 815 835 19 16.91
v 1046 1066 19 16.11
b 568 588 19 17.56
b 741 761 19 16.87
u 312 561 245 18.03
u 312 561 245 18.02
u 716 736 19 16.14
uvw1 692 712 19 16.76
uvw2 1022 1041 19 >17.97
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).