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[vsnet-obs 2007] Re: New on the CV Home Page





Concerning the article "Why Observe Z Cam stars?" by
F.A.Ringwald (http://vsnet.cv.psi.edu/pages/frzcam.html).

> We know, for example, that Z Cam itself was in standstill from 1978 to 1981.
> In contrast, HX Peg has much shorter standstills, about 30 to 90 days long,
> which recur yearly.
Also Z Cam show the last year 4 short time standstills; the duration
of three standstills are approximately a "normal" outburst cycle time 
and ended with a faint maximum or flare (\delta 0.2-0.3mag),
e.g. http://aibn55.astro.uni-bonn.de:8000/~jpietz/pix/zcam3.gif

> The pre-standstill behavior may be an important clue:
> often, the minima get brighter, the maxima get fainter, and the amplitudes
> of the outbursts get smaller. Somehow, a Z Cam star knows it will go into
> standstill some months before it actually does.
The pre-standstill behavior is shown in
http://aibn55.astro.uni-bonn.de:8000/~jpietz/pix/zcam.gif

Comments? Can somebody confirm this behaviour by his data?

Regards, Jochen Pietz
 

--------------------------------------------
Jochen Pietz
jpietz@astro.uni-bonn.de
http://aibn55.astro.uni-bonn.de:8000/~jpietz