GCN Circular 10078
Subject
GRB091024 Swift/UVOT Upper Limits
Date
2009-10-25T11:05:38Z (15 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) and F. E. Marshall (NASA/GSFC) report on behalf
of the Swift/UVOT team:
The Swift/UVOT began observerving the field of GRB 091024 ~3ks
after the BAT trigger (Marshall et al., GCN Circ. 10062). No
optical afterglow is detected in the UVOT exposures at
the refined position of the X-ray afterglow (Page et al.,
GCN Circ. 10069) and the position reported by Faulkes
Telescope North (Mundell., et al., GCN Circ. 10063).
The 3 sigma upper limits for the b, u, uvw2 and summed uvw1
exposures are reported below.
Filter T_start(s) T_stop(s) Exposure(s) 3sigma Upper Limit
-------------------------------------------------------------------
b 45981 45984 3 > 17.31
u 32984 33055 70 > 19.03
uvw1 26617 38935 1283 > 20.37
uvw2 3151 3161 10 > 17.28
-------------------------------------------------------------------
The above magnitudes are not corrected for the Galactic extinction
corresponding to a significant reddening of E_{B-V} = 0.99 mag
(Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383,627).