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GCN Circular 8283

Subject

GRB 080922: Swift/UVOT Upper Limits

Date

2008-09-23T14:52:56Z (16 years ago)

From

Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and B. Sbarufatti (INAF-IASFPa)
report on the behalf of the Swift UVOT team:

      The Swift/UVOT observed the field of GRB 080922 starting 13,904 s
(= 3.84 hr) after the INTEGRAL detection (Mereghetti et al. 2008, GCN
Circ. 8281Not found
 
 
).  We do not find any new source, relative to the DSS or
2MASS, or any variable source inside the INTEGRAL/IBAS error circle.
The 3-sigma upper limits for detecting a source in the co-added
images, using a 2.5 arcsecond radius circular aperture, are:

Filter  T_start   T_stop   Exp(s)     Mag
-----------------------------------------
    v     15,622   15,834     208    >18.9
    b     14,550   26,731     625    >20.6
    u     14,333   31,298     834    >20.3
  uvw1    13,904   30,081    1668    >20.5
  uvm2    15,839   15,853      14    >16.1
  uvw2    14,769   27,419    2341    >20.8
-----------------------------------------

The quoted upper limits have not been corrected for the expected, and
highly uncertain, Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 20 mag (Schlegel, et al.,
1998, ApJS, 500, 525).  All photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383, 627).