[vsnet-grb-info 21565] GRB 190109B: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23664
SUBJECT: GRB 190109B: Swift/UVOT Upper Limits
DATE:    19/01/09 20:37:32 GMT
FROM:    Kira Simpson at PSU  <kira.simpson1984 at gmail.com>

GRB 190109B: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 190109B
91 s after the BAT trigger (Sbarufatti et al., GCN Circ. 23648).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 23652)
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            91          241          147         >20.7
u_FC               303          553          246         >20.7
white               91         6461          727         >22.1
v                  634         6860          441         >20.4
b                  559         6256          432         >20.9
u                  303         6050          470         >21.0
w1                 683         5845          236         >20.2
m2                5440         5640          197         >20.8
w2                5030         6666          393         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.72 in the direction of the burst
(Schlegel et al. 1998).