[Aavso-photometry] Variability of GSC 2362-2866

[Pierre de Ponthiere]

I've observed a star having a similar light curve : GSC 1874:399 close
to FS Aur.
The star variability has been discovered by J. Robertson in 2004.
The maxima in phase curve at 0.25 and 0.75 are also different but for
this star the maximum value is at 0.75 instead of 0.25.
The phase curve is available on my website http://users.skynet.be/dppobservatory
Pierre
--
Pierre de Ponthiere (Belgium)
CAB Member (Cercle Astronomique de Bruxelles)
AAVSO and CBA Observer
http://users.skynet.be/dppobservatory

On 1/26/06, Dirk Terrell <terrell at boulder.swri.edu> wrote:
> On Thu, 26 Jan 2006 16:30:21 +0200, Pertti P„„kk"nen wrote:
>
> >Let me introduce our observation of GSC 2362-2866 in Perseus, which was found
> >to be a variable star during ITM's observation of (93)Minerva. The star
> >appears to be a W UMa eclipsing binary with 7 hours period and variability
> >between V=13.45...14.05. Results of 395 observations and analysis are
>
> That could potentially be an interesting system. The difference in the
> eclipse depths indicates a difference between the surface temperatures
> of the two stars, meaning that the thermal coupling is very weak (or
> non-existent) and the system might be one of the rare "broken contact"
> systems. When the contact is broken, the system becomes semi-detached
> with the primary filling the Roche lobe. Because of the expansion of
> the primary (due to the fact that it can no longer dump a large
> fraction of its luminosity into the secondary), it will transfer matter
> to the secondary (which has shrunk away from its Roche lobe because it
> is no longer puffed up by that energy from the primary) and there will
> be an impact hot spot on the secondary. This will cause the light curve
> maximum at phase 0.25 to be higher than at 0.75 (0.0 being the primary
> minimum). That is clearly the case in your light curve. Additional U, B
> and I photometry would be very useful for this system. Unfortunately
> the eclipses appear to be partial and that will limit what a full
> analysis of the light curve can tell you, primarily that you cannot get
> the mass ratio from the photometry alone so you will need radial
> velocities of both stars to figure everything out.
>
> Dirk
>
> ---
> Dr. Dirk Terrell
> Computer and Mission Systems Section Manager/Astronomer
> Southwest Research Institute, Boulder, CO
> 303-546-9670
> http://www.boulder.swri.edu/~terrell/
>
>
>
> _______________________________________________
>
> Aavso-photometry mailing list
> Aavso-photometry at mira.aavso.org
> http://www.aavso.org/mailman/listinfo/aavso-photometry
>