[vsnet-grb-info 20605] GRB 180510B: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22703
SUBJECT: GRB 180510B: Swift/UVOT Detection
DATE:    18/05/11 11:34:44 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

S. R. Oates (U.Warwick) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180510B
2954 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22696).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 22698)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
  RA  (J2000) =  05:11:52.60 =  77.96918 (deg.)
  Dec (J2000) = -62:19:26.7  = -62.32408 (deg.)
with an estimated uncertainty of 0.47 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 (FC)        2954         3103          147         18.29 +/- 0.09
white             4135         4335          196         18.81 +/- 0.12
v                 3111         3310          197         18.00 +/- 0.19
b                 3931         4130          197         18.99 +/- 0.29
u                 3725         3925          197         17.96 +/- 0.16
w1                3520         3720          197         18.82 +/- 0.31
m2                3315        10201          663         19.75 +/- 0.30
w2                4341         4541          197        >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).