NOTE: uvot_fluxes_wget.pl vrs. 2018-11-07 fem at 200224d20h30m54s966976usUT
NOTE: Source region spec. is: 248.7674 +41.6118 3"
NOTE: Used archived uvot source position of 248.76740  41.61180  3.00
NOTE: position reference is GCN_Notice
NOTE: A UVOT position was reported in GCN_Notice_Mon_24_Feb_20_14:53:25_UT
NOTE: Possible detection in uu at T+259.1
NOTE: Possible detection in wh at T+861.1
WARNING: t_start for light curve (259) and t_start from the exposure report (101) do not agree.
  Replace ??? in draft Circular with correct value.

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

GRB 200224A: Swift/UVOT Upper Limits

F. E. Marshall (NASA/GSFC) and T. N. Ukwatta (LANL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200224A
***???*** s after the BAT trigger (Ukwatta et al., GCN Circ. 27173).
No optical afterglow consistent with the XRT position
(Gropp et al. GCN Circ. 27179)
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           861         1011          147         >20.1
u_FC               259          509          246         >18.5
white              861         1011          147         >20.1
u                  259          509          246         >18.5
w1                5977        47285         3045         >21.8
m2                5772        46378         3050         >21.7
w2                5363        30092         1953         >21.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.005 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 200224A: Swift/UVOT Detection

F. E. Marshall (NASA/GSFC) and T. N. Ukwatta (LANL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200224A
***???*** s after the BAT trigger (Ukwatta et al., GCN Circ. 27173).
A source consistent with the XRT position
(Gropp et al. GCN Circ. 27179)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  16:35:04.15 = 248.76730 (deg.)
    Dec (J2000) = +41:36:42.2  =  41.61172 (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              861         1011          147         20.57 +/- 0.20
u                  259          509          246         18.77 +/- 0.10
w1                5977        47285         3045        >21.8
m2                5772        46378         3050        >21.7
w2                5363        30092         1953        >21.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.005 in the direction of the burst
(Schlegel et al. 1998).