NOTE: Possible detection in wh at T+139235.5

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

GRB 150101B: Swift/UVOT Upper Limits

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150101B
139236 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
No optical afterglow consistent with the XRT position
*** POSITION REFERENCE is xrt_web_site ***
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 initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white           139236       178572         8684         >18.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.041 in the direction of the burst
(Schlegel et al. 1998).


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

GRB 150101B: Swift/UVOT Detection

***UBS*** (***INSTITUTION***) and ***BA*** (***BA INSTITUTION***)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 150101B
139236 s after the BAT trigger (***Author*** et al., GCN Circ. ????).
A source consistent with the XRT position
*** POSITION REFERENCE is xrt_web_site ***
is detected in the initial UVOT exposures.

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           139236       139297           61         18.87 +/- 0.12

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.041 in the direction of the burst
(Schlegel et al. 1998).