[vsnet-grb-info 10936] GRB 110915A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12355
SUBJECT: GRB 110915A: Swift/UVOT Upper Limits
DATE:    11/09/17 20:18:06 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten at astro.psu.edu>

E. A. Hoversten (PSU) and S. T. Holland (CRESST/USRA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110915A  
84 ks after the BAT trigger (Holland et al., GCN Circ. 12335).  No  
optical afterglow consistent with the enhanced XRT position (Evans et  
al., GCN Circ. 12340) is detected in the initial UVOT exposures.   
UVOT magnitude 3-sigma upper limits are reported in the following table:

Filter  T_start  T_stop  Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white      84     1884    429       > 21.46
v         616     5316    203       > 19.35
b         540     1858    136       > 20.10
u         284     1834    362       > 20.36
uvw1      665     1809    136       > 19.59
uvm2      641     1784    136       > 19.46
uvw2      592     1897    144       > 19.82

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.06
(Schlegel et al. 1998). All photometry is on the UVOT photometric  
system described in Poole et al. (2008, MNRAS, 383, 627).