[vsnet-alert 125] Re: Rare Outburst of V795 Cyg (& AL Com)

[tkato@kusastro.kyoto-u.ac.jp]

Dear Colleagues,

   To make our knowledge of V795 Cyg more complete, I would like to add
some outburst records of this dwarf nova.

   The discovery paper in Vatican Ric. Astr. gave following dates of
maxima.  From this article, I have estimated the outburst duty cycle
(fraction of observations brighter than mag 14.0) as 0.016.  This value
is one of the smallest among dwarf novae confirmed or suspected to be
above the period gap.  The observation of the current outburst might
provide a clue in understading the physics of dwarf novae of this kind.

    JD        mpg      comment
  2433982     13.5     two plates
    35303     13.5     three plates, fainter than 16.4 on 35309
    35623     14.6     isolated plate

   The early VSOLJ record gives two outbursts in 1987 and 1988, the one
in August 1987 was probably the first visually observed outburst.  Upon
notification by P. Schmeer, I obtained a 1.5-hour CCD photometry during
November 1992 outburst.  The current dwarf nova classification (UGSS) is
based on apparent absence of superhumps in this photometric run.

Regards,
Taichi Kato

PS.  We have missed AL Com since Apr. 28 observation due to the very cloudy
     or rainy weather.  Does anyone know observations since?  Has any "dip"
     occurred?

     Our observation on Apr. 28 still clearly showed superhumps, and we have
     revised the estimate of the superhump period of this system as 0.05728
     day, which is 1.1 +/- 0.2 percent longer than the period determined
     from the early low-amplitude modulation (cf. IAUC 6164; we interpret
     this as something related to the orbital period).

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