Swift J001159.1+522440: FTW optical observations
ATel #17137; Malte Busmann (LMU), Brendan O'Connor (Carnegie Mellon U.), Daniel Gruen (LMU), and Antonella Palmese (Carnegie Mellon U.)
on 7 Apr 2025; 13:06 UT
Credential Certification: Malte Busmann (m.busmann@physik.lmu.de)
Subjects: Optical, X-ray, Transient
We observed the UV and X-ray transient Swift J001159.1+522440 (Evans et al., ATel #17128) with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW) in the g r and z band. We took 14 x 180 s exposures in the r and g band starting at 2025-04-05T02:07:04 and 2025-04-05T02:42:26 respectively. In parallel, we obtained 28 x 180 s exposures in the z band. We detect the source at:
g ~ (20.00 +/- 0.03) mag
r ~ (19.53 +/- 0.02) mag
z ~ (18.74 +/- 0.02) mag
which is significantly brighter than the archival PS1 magnitudes of g~21.1 mag, r~19.8 mag and z~18.8 mag. In the difference imaging with templates from PS1 we detect it at:
g ~ (20.26 +/- 0.05) mag
r ~ (20.28 +/- 0.05) mag
z ~ (19.22 +/- 0.07) mag
with no visible offset from the underlying source.
The magnitudes are calibrated against the PS1 catalog and not corrected for Galactic extinction.
We thank Michael Schmidt from the Wendelstein Observatory staff for obtaining these observations.
