[vsnet-chat 1073] Re: (fwd) IP Peg eclipse timing (Masi)

[Taichi Kato <tkato>]

Re: [vsnet-chat 1065] (fwd) IP Peg eclipse timing (Masi)

Gianluca Masi wrote:

> finally I found the reason of the difference between our heliocentric
> correction values for current IP Peg eclipses. It was in a printing
> error of the text were I took the Binnendijk's formula. Now, I have
> written a short DOS software to evaluate it, obtaining, for the minimum
> I observed on July the 17,

   Thank you for your confirmation, and nice light curves on your WWW
pages.  The scatter in the eclipse light curve looks even smaller than
what we had previously observed!  Please continue your good works, and
I look forward to seeing your thses and forthcoming results in publication.

   Well, although the discrepancy in heliocentric correction between us
has been reduced to 5 sec, it will be still significant in fine analysis
of eclipsing CVs.  Five seconds roughly corresponds to 0.01 AU, which
difference looks too large for any (even rough) conventional ephemeris
of the earth.  Does Binnendijk's formula correctly treats the eccentricity
of the earth's orbit?

   On our previous timing analysis of HT Cas (that outburst in 1995)
eclipses, the (nominal) standard error of eclipses (coadded) reached 0.3 sec.
This degree of accuracy in heliocentric (or barycentric) correction may be
the absolute requirement.

Regards,
Taichi Kato

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