NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 200307d18h01m22s033929usUT
NOTE: Source region spec. is: 198.55602 11.26985 3"
NOTE: Used archived uvot source position of 198.55602  11.26985  3.00
NOTE: position reference is GCN_Circ_27326
NOTE: A UVOT position was reported in GCN_Circ_27326
NOTE: Possible detection in uu at T+117.5

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

GRB 200306C: Swift/UVOT Upper Limits

J. D. Gropp (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200306C
118 s after the BAT trigger (Gropp et al., GCN Circ. 27326).
No optical afterglow consistent with the XRT position
(Gropp et al. GCN Circ. 27326)
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

u_FC               118          367          246         >16.8
u                  118         1026          393         >17.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 200306C: Swift/UVOT Detection

J. D. Gropp (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200306C
118 s after the BAT trigger (Gropp et al., GCN Circ. 27326).
A source consistent with the XRT position
(Gropp et al. GCN Circ. 27326)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  13:14:13.46 = 198.55607 (deg.)
    Dec (J2000) = +11:16:11.7  =  11.26992 (deg.)
with an estimated uncertainty of 0.43 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

u                  118          367          246         16.88 +/- 0.04

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).