[vsnet-alert 6872] 1RXS J232953.9+062814 superhumps persist!

[Taichi Kato <tkato>]

1RXS J232953.9+062814 superhumps persist!

Dear Colleagues,

    In addition to the preceding report by Uemura-san, we have received
further data from T. Vanmunster, D. Starkey and T. Krajci (three nights).
Together with the data from J. Pietz (three nights) and Kyoto data,
all the phases of the recent rebrightening have been exceptionally perfectly
covered!

    The most striking feature during this rebrightening was the appearance
of double-wave humps, growing at the rebrightening peak (caught in Krajci's
observation).  The same signal, sometimes singly peaked, and sometimes
doubly peaked, continues up to the most recent observation.  Preliminary
period analysis has shown that the signal has the same period as the
superhump period, as suggested by T. Vanumunster.

    Such a growth of the superhump signal at the (short) rebreightening
peak is totally unprecedented!  Even WZ Sge showed more "moderate" superhump
signatures during its repeated rebrightening stage.

    Together with the apparent shortness of the superoutburst plateau,
the long persistence of the superhump signal, and the short recurrence
time, the star may be an analogue of RZ LMi and DI UMa, the shortest
period ER UMa stars with a lot of enigmas.  This object may be the first
example of the existence of such objects below the CV period minimum.
If this possibility is confirmed, this object would provide the first
clear evidence of mass-transfer mechanism other than the gravitational
wave radiation (GWR) below the CV period minimum.

    In order to test this possibility, further detailed, dense observations
through the whole supercycle (if any), and entire coverage of superhumps
are of utmost importance.

    Further detailed analysis will be presented by Uemura-san, together
with the web update.

Regards,
Taichi Kato
on behalf of the VSNET Collaboration team

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