GCN Circular 9106
Subject
GRB 090407: Swift UVOT Upper Limits
Event
Date
2009-04-07T21:34:44Z (17 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) and H. Ziaeepour (MSSL-UCL) report on behalf
of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 090407 98 s
after the BAT trigger (Ziaeepour et al., GCN Circ. 9101). No
optical afterglow is detected in the initial UVOT exposures at
the refined position of the X-ray afterglow (Evans et al., GCN Circ.
9105).
The 3 sigma upper limits for the finding chart (fc) and summed
exposures are reported below.
Filter T_start (s) T_stop Exposure Mag/3UL
------------------------------------------------------------
white fc 98 248 147 <20.50
u fc 310 559 246 <19.89
white 590 2050 303 <21.04
v 640 5550 352 <19.25
u 713 2001 136 <19.61
b 565 2026 156 <19.99
uvw1 689 1977 136 <19.35
uvm2 664 5607 207 <19.49
uvw2 615 2071 170 <19.74
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.40 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).