[vsnet-alert 9520] Possible new variable star in Cygnus

[Herman Mikuz]

Possible new variable star in Cygnus

In the course of Comet and Asteroid Search Program (PIKA) at Crni Vrh
Observatory, a possible variable star was detected on 4 unfiltered CCD
images taken around 2007 Aug. 19.89UT with a 60-cm, f/3.3 Cichocki
reflector. The new object is located at 19:36:40.95, +33:26:06.3
(equinox 2000.0). This position is accurate within about 0.2". The
object is at magnitude about 15.2+-0.05, roughly equivalent to R band.

There is a faint object at the edge of detectability close to this
position on POSSII J images obtained from Aladin.  Also, there is an
object of mag 17.6R in in USNO A2.0 catalogue at 19:36:41.34, +33:26:04.60.

In the meantime, we obtained the following R and B filter
CCD photometry using  a 0.60-m f/3.3 Cichocki reflector and USNO-B1 R2
catalogue:

2007 Aug. 23.870UT R=16.14 +/- 0.04; B=16.19 +/- 0.05
2007 Aug. 25.939UT R=16.35 +/- 0.07
2007 Aug. 26.880UT R=16.51 +/- 0.07; B=16.71 +/- 0.07

These measurements indicate that the object is in a slow decline.

Between 2007 Aug 25.855UT and Aug 25.979UT, we obtained 3 hours of
CCD R band photometry using the same telescope. The light curve
show quasi periodic 0.1-0.4 mag amplitude short oscillations
(see the http://www.observatorij.org/Data/iauc/graf2.gif)
We have probably not enough data to determine the variable type.

As we are unlikely to be able to obtain further observations
in the next days due to bad weather, members of VSNET might want to
take follow-up observations and possibly find the true nature of
this object.

Jure Skvarc, Bojan Dintinjana and Herman Mikuz,
Crni Vrh Observatory
http://www.observatorij.org/