[vsnet-grb-info 24793] GRB 200125A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26892
SUBJECT: GRB 200125A: Swift/UVOT Upper Limits
DATE:    20/01/27 01:22:25 GMT
FROM:    Kira Simpson at PSU  <kira.simpson1984 at gmail.com>

GRB 200125A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200125A
179 s after the BAT trigger (Lien et al., GCN Circ. 26876).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 26878)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           179          329          147         >20.4
white              179         4176          344         >21.1
v                 4387         4586          197         >18.4
b                 3771         3971          197         >19.9
u                  337          414           75         >18.9
w1                4796         4835           38         >18.6
m2                4591         4791          197         >19.3
w2                4182         4382          197         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).