TITLE:   GCN CIRCULAR
NUMBER:  6291
SUBJECT: GRB 070411: Swift/UVOT observations
DATE:    07/04/12 14:00:03 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S.R.Oates (UCL-MSSL) and A. Moretti (INAF-OAB) report on behalf of the
Swift/UVOT team:

The Swift/UVOT began observing the field of GRB 070411 on 2007-04-11 at 
20:16:37 UT, 243s after the BAT trigger (Moretti et al., GCN 6267). A weak 
afterglow is detected in the WHITE, V and B filters at a refined position:

RA(J2000)  =  07:09:19.903
Dec(J2000) = +01:03:52.95

The magnitudes and 3 sigma upper limits are provided in the table below.
The numbers in square brackets represent the significance of the detections.

Filter  Start(s)   End(s)      Exposure    Magnitude
-----------------------------------------------------------------
WHITE   242.9      342.7       98.2      18.76 +/- 0.13		[8.3]
WHITE   4418.0     4617.8      196.6     20.56   (3sigma UL)

V       349.2      368.9       19.5      17.40 +/- 0.33		[3.3]
V       4827.9     4911.8      82.6      18.81   (3sigma UL)

B       445.9      455.7       9.6       19.02 +/- 0.65	        [1.8]
B       4213.5     4413.2      196.6   	 20.56 +/- 0.51         [2.1]

U       421.5      4208.2      216.1     19.87   (3sigma UL)

UVW1    397.5      16931.8     833.9     20.89   (3sigma UL)

UVM2    373.1      16297.4     1326.0 	 21.38   (3sigma UL)

UVW2    474.9      4823.2      216.1     20.37   (3sigma UL)
------------------------------------------------------------------

These magnitudes are not corrected for the Galactic reddening of E(B-V)=0.285.
The value of the Galactic reddening is uncertain as the burst lies at a 
Galactic latitude of +5 degrees.