[vsnet-alert 15757] new paper on Kepler observation of SU UMa-type dwarf novae

[Taichi Kato]

   And here is another.  Just have a look at the light curves.

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arXiv:1305.5636
Date: Fri, 24 May 2013 07:17:29 GMT   (1185kb)

Title: Analysis of Three SU UMa-Type Dwarf Novae in the Kepler Field
Authors: Taichi Kato (Kyoto U.), Yoji Osaki (U. of Tokyo)
Categories: astro-ph.SR
Comments: 23 pages, 18 figures. Accepted for publication in PASJ
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  We studied the Kepler light curves of three SU UMa-type dwarf novae. Both the
background dwarf nova of KIC 4378554 and V516 Lyr showed a combination of
precursor-main superoutburst, during which superhumps always developed on the
fading branch of the precursor. This finding supports the thermal-tidal
instability theory as the origin of the superoutburst. A superoutburst of V585
Lyr recorded by Kepler did not show a precursor outburst and the superhumps
developed only after the maximum light, a first example in the Kepler data so
far. Such a superoutburst is understood within the thermal-tidal instability
model. The observation of V585 Lyr made the first clear Kepler detection of the
positive period derivative commonly seen in the "stage B" superhumps in dwarf
novae with short orbital periods. In all objects, there was no strong signature
of a transition to the dominating stream impact-type component of superhumps,
suggesting that there is no strong indication of an enhanced mass-transfer
following the superoutburst. We have determined the orbital period of V516 Lyr
to be 0.083999(8) d. In V516 Lyr, some of outbursts were double outbursts in a
various degree. The preceding outburst in the double outburst was of the
inside-out nature while the following one was of the outside-in nature. One of
superoutbursts in V516 Lyr was preceded by a double precursor. The preceding
precursor failed to trigger a superoutburst and the following precursor
triggered a superoutburst by developing positive superhumps.
\\ ( http://arxiv.org/abs/1305.5636 ,  1185kb)