[vsnet-ip 36] On HT Cam (RX J0757.0+6306)

[Taichi Kato <tkato>]

On HT Cam (RX J0757.0+6306)

  Two previous messages related to this object:

   [vsnet-alert 4846] Patrick Schmeer

> The most recently recorded outburst of this intermediate polar candidate
> was detected by me on 1999 May 22.949 UT at mv= 13.0 (cf. vsnet-alert
> 3014, 3025; see also vsnet-chat 2890). The only other visually detected
> outburst was found by H. Itoh on 1997 Dec. 12.866 UT at mv= 12.9 (vsnet-
> alert 1379). All recorded brightenings were extremely short (duration
> about 1 day).

   [vsnet-campaign 78] Simon and Kato

> > Although the sky was light due to almost full Moon, HT Cam was
> > clearly detected in R filter (exp. time 90 sec).
> > HT Cam is back in quiescence because it looks similarly faint
> > as in the image published by Tovmassian et al. (A&A, 335, 227 (1998)).
> >
> > It confirms rapid decline from outburst, in agreement with the previous
> > ones.
> 
>    Great finding!  Such a rapid decline from full dwarf-nova looking (more
> than 5 mag?) outbursts may indicate the discovery of a new class of CVs or
> phenomena.  Perhaps several other objects may have similar missed or
> unconfirmed outbursts.  What an excitement of the world of transients!

   I have reviewed the available spectra of the object, and rather
surprized to find weak He II lines compared to those well-known magnetic
CVs.  The spectra look more similar to those of short-period dwarf novae
with low mass-transfer rates.  We may have to look for the cause of
surprizingly short outbursts, other than the originally suggested
intermediate-polar nature.  Yes, the object still could be a good candidate
SU UMa/WZ Sge star.

Regards,
Taichi Kato

PS. Have we missed the early 2001 outburst, or the one will be due?

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