[vsnet-alert 14164] Re: Outburst of a possible new cataclysmic variable 1RXS J063214.8+253620

[Denis Denisenko]

Congratulations to Stas Korotkiy and Kirill Sokolovsky on discovering
this interesting object!

While the 20-cm telescope with DSI Pro II is taking time series of
J0632+2536 outside at -13C, I have checked the catalogs information
about this star.

SDSS DR7 has *two* objects (or, better to say, two records) at the
position of the new variable separated by 0.6":

1) SDSS J063213.08+253622.0 with Type specified as GALAXY (weird!) and
weird (g-r), (r-i) color indices:
u=18.21 g=17.92 r=16.57 i=17.06 z=16.81
http://cas.sdss.org/astrodr7/en/tools/explore/obj.asp?id=758884820114670566

2) SDSS J063213.10+253622.6 (Type = STAR)
u=16.60 g=15.66 r=15.48 i=14.87 z=14.76
http://cas.sdss.org/astrodr7/en/tools/explore/obj.asp?id=758884820114670564

Visual inspection of SDSS image shows that *many* stars in this area
are elongated in the same direction as the new variable, thus the
"double" nature of this object in SDSS is likely fictious, being
perhaps a processing artefact.

Visual inspection of digitized Palomar images from 1949 (POSS-I), 1990
(POSS-II R), 1996 (POSS-II B) and 1997 (POSS-II IR) definitely shows
the proper motion about 1.5" in 40 years, in full agreement with
USNO-B1.0 values of pmRA=-30, pmDE=-20.

Finally, infrared magnitudes of 2MASS 06321311+2536229 are definitely stellar:
J=13.60+/-0.02, H=13.18+/-0.03, K=13.01+/-0.03

Denis Denisenko

2012/1/28 Seiichi Yoshida <comet at aerith.net>:
> Dear Korotkiy Stas,
>
>> Here is our astrometry of this object.
>>   R.A. 06h32m13s.09, Decl. +25o36'22".2 (J2000.0)
>
> Note that the astrometry above is based on all of our images from 2011
> Jan. 10 to 2012 Jan. 26.
>
> The astrometry based on only the outburst images on 2012 Jan. 26 is:
>  R.A. 06h32m13s.12, Decl. +25o36'21".8 (J2000.0)
>
> There is a USNO-A2.0 star at this position:
>  USNO-A2.0 1125.04125863  06h32m13s.235 +25o36'23".97  Mag(R):14.5  Mag(B):15.4
>
> However, we cannot say whether this USNO-A2.0 15-mag star became
> bright, or a new bright star appeared very near by this position,
> based on our astrometry.