GCN Circular 16241
Subject
GRB 140509A: Swift/UVOT Detection and photo-z
Date
2014-05-09T17:42:38Z (10 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140509A
121 s after the BAT trigger (Page et al., GCN Circ. 16230).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 16233)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 03:06:22.69 = 46.59456 (deg.)
Dec (J2000) = -62:38:21.7 = -62.63935 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 121 271 147 17.00 +/- 0.03
v 610 630 20 16.50 +/- 0.13
b 536 556 20 17.04 +/- 0.10
u 280 530 246 16.35 +/- 0.03
w1 659 7011 490 >20.6
m2 634 6806 490 >21.1
w2 585 6396 432 >20.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).
The lack of detections in the UV filters suggests a redshift of about 2.4.