GCN Circular 23965
Subject
GRB 190311A: Swift/UVOT Detection
Date
2019-03-13T16:33:25Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190311A
88 s after the BAT trigger (Troja et al., GCN Circ. 23946).
A source consistent with the XRT position (Goad et al., GCN Circ. 23950)
is detected in the initial UVOT exposures. This source is consistent
with the initial transient reported by UVOT, Mondy (Pozanenko et al., GCN
Circ. 23947), Next (Zhu et al., GCN Circ. 23948), MASTER (Gorbovskoy, GCN
Circ. 23949), TSHAO (Belkin et al., 23951), GMG (Mao et al., GCN Circ. 23954)
and OAO (Peris et al., GCN Circ. 23959). The source faded below detection by the second
orbit.
The preliminary UVOT position is:
RA (J2000) = 14:08:15.71 = 212.06546 (deg.)
Dec (J2000) = +53:30:02.9 = 53.50080 (deg.)
with an estimated uncertainty of 0.49 arc sec. (radius, 90% confidence).
Preliminary detections 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 88 238 147 19.59 +/- 0.10
white 5678 7314 393 >21.42
white 51260 58205 2454 >22.45
u 301 550 246 19.85 +/- 0.20
u 6704 18770 1081 >21.08
b 6910 19082 493 >20.89
v 6089 12525 1164 >20.42
uvw1 6500 28478 1676 >20.98
uvm2 6294 23285 1557 >20.87
uvw2 5884 7521 393 >20.16
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).