Skip to main content
Announcing GCN Classic Migration Survey, End of Legacy Circulars Email. See news and announcements

GCN Circular 34351

Subject
GRB 230805B: Swift/UVOT Upper Limits
Date
2023-08-06T18:02:19Z (a year ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
Via
legacy email
GRB 230805B: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230805B
196 s after the BAT trigger (Cenko et al., GCN Circ. 34339).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 34345)
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           196          345          147         >20.2
u_FC               354          604          246         >19.5
white              196         1878          284         >20.7
v                  683         1927          135         >19.0
b                  610         1854          136         >20.4
u                  354         1829          363         >19.6
w1                 732         1804          117         >19.4
w2                1014         1730           58         >18.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.014 in the direction of the burst
(Schlegel et al. 1998).

Looking for U.S. government information and services? Visit USA.gov