[vsnet-alert 14921] Re: Possible bright CV in Peg? - PNV J23272715+0855391

Denis Denisenko d.v.denisenko at gmail.com
Fri Sep 14 06:52:25 JST 2012

Dear all,

This dwarf nova is definitely identical to the blue star SDSS
J232727.14+085538.7 with magnitudes u=22.09 g=21.83 r=22.03 i=22.26
z=21.87 (see http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237678905705300410)
and to the UV source with two entries in GALEX catalog:

GALEX J232727.1+085538 (FUV=21.48 NUV=21.66)
GALEX J232727.1+085539 (FUV=21.73 NUV=22.00)

An object with such a large outburst amplitude should most likely be a
WZ Sge-type DN, this is why it is really surprising that it had an
outburst just 12.5 years ago. I made a simple virtual experiment with
NSVS data checking the light curve of a nearby star 2MASS
23272242+0855291 (J-K=0.74) 1.2' away, and it also has an outburst in
ROTSE-I data: http://skydot.lanl.gov/nsvs/star.php?num=11851348&mask=32004
(though on the different date). Not that I don't trust NSVS - after
all, I have found there a real outburst of RX J2319.6+3647 blended
with a 14.2m star 18" away. What I want to say is: perhaps two
outlying points on a single night are not an "ironclad" evidence of
the outburst.

Anyways, I am doing the time series of this star right now from the
roof of DNTTM in Moscow with the new 10" MEADE LX90 GPS and QHY9 CCD.
This is only the "second light" of our new setup, scope is not
perfectly collimated, alt-az mount is glitching near the meridian, and
last night the 12V power supply battery exhausted after 5 hours of
work. Hope tonight it will last long enough to obtain a light curve
useful for measuring the period. Starting from tomorrow we will have
clouds, according to the forecast.

Thanks a lot to Koichi Itagaki for such an interesting target!

Denis in Moscow

P.S. I have also noticed an obvious proper motion of the star between
two Blue DSS plates. The images are on my laptop which is connected to
the CCD camera, while I am writing this from the public PC which is
very slow. More details later.

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