[vsnet-alert 12790] ER UMa: long-lasting quiescence with negative superhumps!

[Taichi Kato]

ER UMa: long-lasting quiescence with negative superhumps!

   Enrique de Miguel has reported new observations.
Negative superhumps have been persistently seen, with a slight variation
in the period.  The amplitudes varied from 0.4 to 0.8 mag, and seem to be
modulated by the beat phenomenon (this phenomenon is not so apparent
during the outbursting phase).
The object still remained in quiescence, even 4 d after the "normal" outburst
following the superoutburst.  Since the mean intervals of normal outbursts
in this system were usually 4 d, the quiescent state seems to be prolonged.
The presence of negative superhumps may have somehow prevented normal
outbursts.  This possibility is very interesting because some SU UMa-type
dwarf novae show remarkably different frequency of normal outbursts
within the same object (e.g. V503 Cyg, 2002PASJ...54.1029K) which appear
to be associated with quiescent negative superhumps.
Further observations are naturally encouraged!