Special Notice #147: Activity in the unusual cataclysmic variable V630 Cas

AAVSO Special Notice #147

Activity in the unusual cataclysmic variable V630 Cas
February 19, 2009

As was discussed by Gary Poyner on the baavss-alert and cvnet-discussion mailing lists, the peculiar cataclysmic variable V630 Cas appears to have brightened significantly above its quiescent level.  It has been suggested that this brightening may be a precursor to an outburst, although that has not been established at this time.  Poyner further notes that the last recorded outburst of V630 Cas was in 1992, when the star rose by two magnitudes, and remained in outburst for three months; the only other known outburst occurred in 1950, when the star rose by 5 magnitudes.

The most recent estimate by Hazel McGee at JD 2454881.585 (2009 Feb 19.085) puts V630 Cas at m(CV)=15.1 based on a visual estimate from a CCD image. This is approximately one magnitude above its normal quiescent value.  The object was also measured at m(CV)=15.14 on JD 2454880.60069 (2009 Feb 18.1007; McGee, reduction by Poyner), and Arne Henden also reports that coincident BVRI data taken at SRO/Arizona indicates V630 Cas was at V=15.14 on JD 2454881.610 (2009 Feb 19.110).  Mike Simonsen noted on aavso discussion a published study by Orosz et al. (2001; MNRAS 326, 1134) indicating the occurrence of occasional variations of 0.2 to 0.4 magnitudes; the current activity appears to have exceeded this range.

Observers are encouraged to continue monitoring this object over the coming days and weeks to follow this activity.  Both visual estimates and instrumental photometry are encouraged.

V630 Cas is located at the following J2000 coordinates:

RA: 23 48 52.0 , Dec: +51 27 39

Charts for V630 Cas may be plotted with VSP at the following URL: http://www.aavso.org/observing/charts/vsp/index.html?pickname=V630%20Cas

Please promptly report all observations to the AAVSO using the name "V630 CAS".

This AAVSO Special Notice was prepared by M. Templeton.


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