Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Mon, 07/27/2015 - 18:51
BC Cas had an nova-like outburst in 1929. But according to T. Zwitter et al in 'Cataclysmic Variables and Related Objects: Proceedings of the 158th Colloquium of the International Astronomical Union' p 94 table 2, it is not showing a CV-like spectrum. So what type could this variable be?
Eddy
Hi Eddy,
This paper by Liu and Hu confirms it spectroscopically as a CV and also quotes other studies that did the same.
The amplitude is small for a typical nova, maybe it is recurrent.
Best wishes,
Sebastian
Hi Eddy
The amplitude in the Downes online cat is given as 10.7-17.4p. Based on just this one characteristic, more suggestive of a UGWZ than a classical nova -- but your quoted paper mentions a non-CV spectrum.
The DSS1, DSS2, and 2MASS images look quite unremarkable as well. Probably no big dusty red giant donor here either a la V745 Sco / V3890 Sgr type of RN.
Perhaps the star that has been identified with BC Cas is in error - maybe we're looking at a close visual companion instead of the real variable. 1929 was quite awhile ago - wonder what the plate scales and limiting magnitudes of the exposures in question were ...
As well ... in the AAVSO DB there are a handful of positives. The most recent one there (STR) seems consistant with Downes' identification. The 2 earlier ones by AAM are perhaps more interesting, or problematic.
I think I also have a positive detection of this one ( as yet unreported) from a couple of years ago, in my image archive. It was either in V or Rc, and around 17m as I remember. Must dig that one out !
What DOES the spectrum show, I wonder ? If non-CV, then maybe EXOR ? Not symbiotic. Mis-identified ?
A Stellar Cold Case ! Thanks for bringing it up.
Steve
Sebastian,
Thanks for (clarifying)
Steve
Thanks Sebastian and Steve for the info! I'll will add this one to my program.
Eddy