[vsnet-j 2432] eta Gem eclipse? in progress

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

eta Gem eclipse? in progress

  eta Gem の食らしき現象が始まっているかもしれない、という報告があります。
　（もし本当ならば８年に１度の現象？なのですが、どうでしょうか）

From: "Sebastian Otero" <varsao@fullzero.com.ar>
Date: Wed, 4 Dec 2002 11:18:45 -0300
Subject: [vsnet-chat 5665] Eta Geminorum eclipse in progress

Dear colleagues,

Although the current fading of eta Geminorum seems to be in phase with the
semiregular pulsation cycle, a close look to the ephemeris makes the
difference. We are probably seeing the descending branch of one of the very
strange eclipses of this long period system (2983-2984 days). I couldn't
find accurate elements, but the GCVS epoch is JD 2437725 and this means
minimum will occur somwhere between JD 2452640 and 645.(December 31-January
4).
Eclipse duration is 5% of the period, which means 74-75 days. This is
exactly when my first point of the season was collected and since then the
fading trend is apparent.
I think it would be interesting trying to see the features of the eclipse
light curve, specially in order to identify the combination of both the SR
and the EA behaviour.
I have uploaded a lightcurve at:

http://ar.geocities.com/varsao/Curva_Eta_Gem.htm

Best regards,
Sebastian.

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