GCN Circular 18489
Subject
LIGO/Virgo G194575: Swift observations of LSQ15bjb
Date
2015-10-27T14:19:38Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), Frank Marshall (NASA/GSFC), J.A. Kennea
(PSU), B. Sbarufatti (INAF-OAB/PSU), Scott Barthelmy (NASA/GSFC), Dave
Burrows (PSU), Sergio Campana (INAF-OAB), Brad Cenko (NASA/GSFC), Neil
Gehrels (NASA/GSFC), Paolo Giommi (ASI), John Nousek (PSU), Paul O'Brien
(U. Leicester), Julian Osborne (U. Leicester), David Palmer
(LANL), Matteo Perri (ASDC), Judy Racusin (NASA/GSFC), Mike Siegel
(PSU), Gianpiero Tagliaferri (INAF-OAB) report on behalf of the Swift team:
Swift performed follow-up observations of the rapidly-brightening
optical transient LSQ15bjb reported by Rabinowitz et al (GCN Circ.
18473) inside the LIGO error region for trigger G194575. The
observations began at 01:20 UT on October 27.
No X-ray sources are found in the image. At the location of the La
Silla-QUEST source there are no events recorded in 2ks of exposure time.
The 3-sigma upper limit deduced from these data is 3.5e-3 ct/sec,
corresponding to an approximate flux of 1.4e-13 erg/cm^2/s.
UVOT took an exposure of 1370 s with the U filter starting at 01:20:05
UT, and a second exposure of 585 s with the U filter starting at
02:36:43. The source LSQ15bjb is detected with a preliminary u magnitude
of 16.79 �� 0.07 in the UVOT photometric system (Breeveld et al. 2011,
AIP Conf. Proce. 1358, 373) in the first exposure and 16.73 �� 0.07 in
the second. We caution that the source is not well separated from the
nearby galaxy.
The magnitudes are not corrected for the Galactic extinction due to the
reddening of E(B-V) = 0.03 in the direction of the source (Schlegel et
al. 1998).
This circular is an official product of the Swift team.