NOTE: uvot_fluxes_wget.pl vrs. 2020-11-03a fem at 210807d14h30m40s326567usUT
NOTE: Source region spec. is: 76.68293 58.24978 3"
NOTE: Used archived uvot source position of  76.68293  58.24978  3.00
NOTE: position reference is GCN_Circ_30600
NOTE: A UVOT position was reported in GCN_Circ_30600
NOTE: Possible detection in uu at T+615.3 sum
NOTE: Possible detection in wh at T+210.2
NOTE: Possible detection in bb at T+465.5
NOTE: Possible detection in vv at T+367.0

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

GRB 210807A: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210807A
210 s after the BAT trigger (Lien et al., GCN Circ. 30600).
No optical afterglow consistent with the XRT position
(Lien et al. GCN Circ. 30600)
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           210          360          147         >17.0
white              210          684          186         >17.2
v                  367          560           39         >16.4
b                  466          660           39         >18.0
u                  441          635           39         >17.6
w1                 416          610           39         >18.2
w2                 515          697           27         >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.409 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 210807A: Swift/UVOT Detection

S. J. LaPorte (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 210807A
210 s after the BAT trigger (Lien et al., GCN Circ. 30600).
A source consistent with the XRT position
(Lien et al. GCN Circ. 30600)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:06:43.89 =  76.68289 (deg.)
    Dec (J2000) = +58:14:59.2  =  58.24979 (deg.)
with an estimated uncertainty of 0.43 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              210          360          147         17.09 +/- 0.03
v                  367          387           20         16.55 +/- 0.18
b                  466          485           20         18.29 +/- 0.31
u                  441          635           39         18.36 +/- 0.33
w1                 416          610           39        >18.2
w2                 515          697           27        >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.409 in the direction of the burst
(Schlegel et al. 1998).