[vsnet-alert 14925] OT J232727.2+085539 variability

Denis Denisenko d.v.denisenko at gmail.com
Fri Sep 14 10:42:43 JST 2012

I have obtained an almost 4-hour long run on this variable from 19:15
UT to 23:13 UT (JD 2456184.301 to 2456184.461), when the shutter of
QHY9 CCD stopped to open properly. There was a short gap in the light
curve from Sep. 13.895 to 13.900 UT when the alt-azimuthal mount of
10" LX90 misbehaved near the meridian kicking the variable out of the
field of view (36'x27' with the f/6.3 focal reducer). Object was
culminating near 21:24 UT at 43 deg elevation. A total of 415
unfiltered 30-sec exposures were obtained, 357 of them were usable for

I have used TYC 1162-506-1 as a reference star with V=11.28 and TYC
1162-506-1 as a comparison star.

The resulting light curve was quite strange. Object has brightened
from 13.90 to 13.80 by JD=2456184.32, then faded to 13.95 by
JD=2456184.345, after which remained nearly constant at this level for
2.5 hours. S/N ratio of the variable on the individual frames was
around 60.

Curiously enough, for the data from 2456184.345 to 2456184.461 alone
("plato" of the curve with points spread between 13.92 and 13.98) the
period search software is suggesting the best value near 0.024d.

Data will be sent to Taichi Kato for analysis.

Denis Denisenko

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