[vsnet-alert 11164] OT J102842.9-081927 further observations (AM CVn-type superoutburst?)

Taichi Kato tkato at kusastro.kyoto-u.ac.jp
Sat Apr 4 10:40:51 JST 2009


OT J102842.9-081927 further observations

   Greg Bolt has reported a further extensive set of observations.
The best period from all the observations was 0.03814(1) d.
There is also a signature of a period increase at dot(P)/P = +14(7)*10^(-5).

   As reported by the KANATA team, the object appears to be a helium
dwarf nova (AM CVn stars) in superoutburst.  The period, however,
exceeds that of GP Com, considered to be WZ Sge-type counterpart among
AM CVn stars without recorded outbursts.  The presence of an outbursting
object having a longer period than that of GP Com is surprising, since
the standard (degenerate branch) evolutionary sequence of AM CVn stars
would predict a smaller mass-transfer rate
(cf. http://adsabs.harvard.edu/abs/1997PASJ...49...75T , fig 4 of
this paper might suggest a heavier primary?).


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