[vsnet-grb-info 26375] GRB 200917A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28475
SUBJECT: GRB 200917A: Swift/UVOT Upper Limits
DATE:    20/09/22 20:13:27 GMT
FROM:    Kira Simpson at PSU  <kira.simpson1984 at gmail.com>

GRB 200917A: Swift/UVOT Upper Limits

K. K. Simpson (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 200917A
104 s after the BAT trigger (Sonbas et al., GCN Circ. 28435).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 28436)
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           104          254          147         >19.9
u_FC               262          512          246         >20.1
white              104         1708          412         >20.5
v                  592         1758          136         >18.9
b                  518         1684          117         >19.5
u                  262         1832          382         >20.2
w1                 641         1807          136         >18.7
m2                1762         1782           19         >18.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.19 in the direction of the burst
(Schlegel et al. 1998).