[vsnet-campaign-dn 3064] V1159 Ori: phase reversal of superhumps occurred!

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

V1159 Ori: phase reversal of superhumps occurred!

Dear Colleagues,

   A preliminary analysis of the current V1159 Ori campaign (observers:
S. Kiyota, K. Torii, K. Tanabe and the OUS team members, R. Ishioka,
D. Nogami, M. Uemura on distributed telescopes) has confirmed that
an unusual phase reversal of the superhumps occurred on November 28
(5 days after the start of the superoutburst).  On November 29,
the strongest signal is about 0.5 phase different from the strong
superhump signal which was observed before November 28.
On November 28, this sudden transition was followed in detail.  This
transition took only several superhump cycles.

   The present observation strongly suggests that the early phase reversal
of the superhumps, which has been first noted in ER UMa (Kato et al.,
astro-ph/0211520) is a common, and possibly unique, feature in ER UMa stars.
The superoutburst of V1159 Ori is still ongoing.  The present visibility
will provide an excellent opportunity to follow the evolution of these
superhumps (late superhumps?) through the entire superoutburst.

Regards,
Taichi Kato
VSNET Collaboration team

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