NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210306d18h31m48s440438usUT
NOTE: Source region spec. is: 129.95813 60.20538 3"
NOTE: Used archived uvot source position of 129.95813  60.20538  3.00
NOTE: position reference is GCN_Circ_29597
NOTE: A UVOT position was reported in GCN_Circ_29597
NOTE: Possible detection in uu at T+297.3
NOTE: Possible detection in wh at T+85.2
NOTE: Possible detection in bb at T+552.6
NOTE: Possible detection in vv at T+627.8

=========== Draft Upper Limit Circular ========

GRB 210306A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and V. D'Elia (SSDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210306A
85 s after the BAT trigger (D'Elia et al., GCN Circ. 29597).
No optical afterglow consistent with the XRT position
(D'Elia et al. GCN Circ. 29597)
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            85          235          147         >16.2
u_FC               297          547          246         >16.7
white               85          597          167         >16.3
v                  628          648           19         >16.8
b                  553          572           19         >17.0
u                  297          547          246         >16.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.052 in the direction of the burst
(Schlegel et al. 1998).


=========== Draft Detection Circular ========

GRB 210306A: Swift/UVOT Detection

K. K. Simpson (PSU) and V. D'Elia (SSDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210306A
85 s after the BAT trigger (D'Elia et al., GCN Circ. 29597).
A source consistent with the XRT position
(D'Elia et al. GCN Circ. 29597)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  08:39:49.98 = 129.95824 (deg.)
    Dec (J2000) = +60:12:19.2  =  60.20533 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections 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               85          235          147         16.23 +/- 0.03
v                  628          648           19         17.44 +/- 0.24
b                  553          572           20         17.32 +/- 0.13
u                  297          547          246         16.87 +/- 0.04

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.052 in the direction of the burst
(Schlegel et al. 1998).