[vsnet-grb-info 20435] GRB 180324A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22531
SUBJECT: GRB 180324A: Swift/UVOT Upper Limits
DATE:    18/03/24 23:27:32 GMT
FROM:    Sam LaPorte at PSU  <sjl5346 at psu.edu>

GRB 180324A: Swift/UVOT Upper Limits

S. J. Laporte (PSU) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180324A
72 s after the BAT trigger (Sonbas et al., GCN Circ. 22524).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 22529) or RATIR position (Butler et al. GCN Circ. 22528)
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            72          221          147         >19.8
u_FC               284          534          246         >19.3
white               72        12383         1552         >21.3
v                  614        13894         1172         >19.5
b                  539         8158          549         >20.9
u                  284         7992          814         >20.3
w1                 664         7787          471         >20.2
w2                6970        13290         1082         >21.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.90 in the direction of the burst
(Schlegel et al. 1998).