GCN Circular 29177

Subject
GRB 201223A: Swift/UVOT Detection
Event
GRB 201223A
Date
2020-12-26T22:03:09Z (5 years ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
���A. Belles (PSU) and J. D. Gropp (PSU)

report on behalf of the Swift/UVOT team:



The Swift/UVOT began settled observations of the field of GRB 201223A

79 s after the BAT trigger (Gropp et al., GCN Circ. 29158Loading...
 
 ).

A source consistent with the XRT position (Goad et al., GCN Circ. 29170Loading...
 
 )

is detected in the initial UVOT exposures.



The preliminary UVOT position is:

    RA  (J2000) =  08:51:09.51 = 132.78961 (deg.)

    Dec (J2000) = +71:10:47.4  =  71.17984 (deg.)

with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).



Preliminary detections and 3-sigma upper limits using the UVOT photometric system

(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:



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



white_FC          79             229            147      16.06+/-0.03

white               571           1019            186      18.04+/-0.08

white             5921           6121            196           >20.17

white           12121         12630            497      20.09+/-0.30

v                      621           1069              58           >17.44

b                      547           1167              58      17.97+/-0.25

b                  11208         12115            885           >20.38

u_FC               292             541            246      16.75 +/- 0.04

u                      694           1142              38           >17.58

w1                   670           1118              58           >17.65

m2                   645           1093              58           >17.87

w2                   596           1045              58           >17.81



The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).