NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210308d18h50m20s352967usUT
NOTE: Source region spec. is: 67.07388 37.43388 3"
NOTE: Used archived uvot source position of  67.07388  37.43388  3.00
NOTE: position reference is GCN_Circ_29619
NOTE: A UVOT position was reported in GCN_Circ_29619
NOTE: Possible detection in wh at T+94.6

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

GRB 210308A: Swift/UVOT Upper Limits

J. D. Gropp (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 210308A
95 s after the BAT trigger (D'Elia et al., GCN Circ. 29619).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is GRB_Auto_Processing ***
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            95          244          147         >18.5
u_FC               307          557          246         >20.1
white               95         1182          353         >19.4
v                  636         1059           58         >18.1
b                  563         1158           58         >19.4
u                  307         1133          285         >20.2
w1                 685         1109           39         >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.296 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 210308A: Swift/UVOT Detection

J. D. Gropp (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 210308A
95 s after the BAT trigger (D'Elia et al., GCN Circ. 29619).
A source consistent with the XRT position
*** POSITION REFERENCE is GRB_Auto_Processing ***
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  04:28:17.73 =  67.07389 (deg.)
    Dec (J2000) = +37:26:02.1  =  37.43391 (deg.)
with an estimated uncertainty of 0.46 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               95          244          147         18.70 +/- 0.07
v                  636         1059           58        >18.1
b                  563         1158           58        >19.4
u                  307         1133          285        >20.2
w1                 685         1109           39        >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.296 in the direction of the burst
(Schlegel et al. 1998).