KAIT Prediscovery Detection of PS1-14xz in NGC 4258 (Messier 106)
ATel #6159; WeiKang Zheng and Alexei V. Filippenko (UC Berkeley)
on 21 May 2014; 21:07 UT
Credential Certification: Weikang Zheng (zwk@umich.edu)
Subjects: Optical, Supernovae
The probable supernova discovered by Pan-STARRS1 (ATel #6156) in NGC
4258 (M106) was observed with the 0.76-m Katzman Automatic Imaging
Telescope (KAIT) as part of the Lick Observatory Supernova Search, with
an average cadence of 3 days. The object was detected in KAIT unfiltered
(roughly R) images obtained on Apr. 09.35, Apr 12.35, Apr. 14.35 UT and
thereafter, but there was no detection in KAIT images obtained on Apr 06.35
with a limiting mag of about 18.0. Preliminary analysis shows that the
target had a rising light curve since the detection on Apr. 09, with an
increase of about 2 mag in the first two weeks. The brightness thereafter
is roughly constant at 15 mag. Owing to the high background and the very
small projected distance from the host nucleus, it is difficult to make a
precise measurement of the brightness, but the light curve is consistent
with that of a Type II-P supernova. The object was not detected by our
pipeline because there are very few field stars and the nuclear region
of the host galaxy is complex.
