[vsnet-grb-info 18017] GRB 160525B: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19465
SUBJECT: GRB 160525B: Swift/UVOT Detection
DATE:    16/05/25 20:09:20 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale at ucl.ac.uk>

M. De Pasquale, N.P. Kuin (UCL-MSSL) and H. A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160525B
88 s after the BAT trigger (Krimm et al., GCN Circ. 19459).
A source consistent with the XRT position (Evans GCN Circ. 19460)
is detected in the initial UVOT white filter exposure.

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               88          238          147         19.8 +/- 0.3
white              581         1894          284        >20.9
v                  631         1945          156        >18.9
b                  556         1870          136        >19.8
u                  300         2018          379        >20.0
w1                 680         1996          156        >19.5
m2                1603         1795           39        >18.2
w2                 606         1573           58        >18.9

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).

-- 

Dr. Massimiliano De Pasquale
Research associate - Swift UVOT scientist
Mullard Space Science Laboratory, University College London