[Aavso-photometry] Eclipsing binary magnitude ranges on AAVSO charts

[Arne Henden]

On Sun, Dec 21, 2008 at 5:16 PM, Patrick Wils <patrickwils at yahoo.com> wrote:
>> If you then look at Simbad's references, you can find some detailed
>> studies of the system.  A particularly good one is
>> Srivastava, R. K., "Photoelectric elements of the eclipsing binary
>> ST Persei," 1970BAICz..21..219S
>>
>> In there, the author gives light curves in B&V, relative to the
>> selected comparison star (BD +38 607; TYC 02851-01660;
>> 03:00:16.79, +39:27:12.1). It shows the differential V range to be
>> -0.3 to +1.5, or 1.8 magnitudes.  If we assume V=9.5 at maximum,
>> this would mean that the star should be 11.3 at minimum,
>> which is why the GCVS gives the range it does.  The range is much
>> more in B, by the way - an amplitude of 2.4 magnitudes.
>
> In 1976AcA....26...15W, Weis and Chen argue that Srivastava included the 11.8V companion (at 11"N from ST Per) in his aperture, so that the real amplitudes in B and V should be 3.6 and 2.8 mag respectively.  This would give mag 12.3V in minimum, much more in agreement with Yenal's observation.
>
Thanks, Patrick!  That solves the problem.  ST Per is then a very nice,
high amplitude eclipsing binary.
Arne