[vsnet-alert 9624] V455 And: fading caused by the termination of ordinary superhumps?

[Taichi Kato]

V455 And: fading caused by the termination of ordinary superhumps?

   As already reported, V455 And showed a sudden fading on Sep 23.
This kind of phenomenon would usually suggest a subsequent rapid
fading stage.  V455 And, however, apparently didn't follow this
general rule.  The present decay rate is far below those recorded
during rapid fading stages in SU UMa-type superoutbursts.
The present phenomenon, in turn, could be interpreted to be
a result of disappearance of the superhump light source, and
the object is now possibly following the underlying general decay.
This interpretation seems to be strengthened by the appearance
of double-wave modulations similar to early superhumps (orbital
signature?) and the apparent absence of ordinary superhumps.
The apparent disappearance of sharp eclipse signature at the
same epoch also could be interpreted as the sudden disappearance
of the superhump light source close to the outer disk rim.
If the above interpretation is correct, the present phenomenon
would be the first evidence for decoupling between 3:1 resonance
and the outbursting disk state.

   In any case, detailed observation at this stage will be vital
to understanding WZ Sge-type phenomenon, and we strongly encourage
further continuous observations as long as possible.

   Further detailed analysis by Maehara-san will follow.