[vsnet-alert 12772] ER UMa: negative superhumps again!

[Taichi Kato]

ER UMa: negative superhumps again!

    Terskol team (Maksim Andreev, relayed by E. Pavlenko), Shiokawa-san,
Enrique de Miguel and Jani Virtanen have reported further observations.

    The data during the present normal(?) outburst clearly demonstrate
the presence of negative superhumps (mean period 0.06260(3) with some
hint of period evolution).  The amplitudes have been steadily growing
from 0.05 mag (end of the rising stage) to 0.25 mag (fading stage).
The amplitudes seem to suggest that these humps were (phenomenologically)
excited in conjunction with the present outburst.  The reported discontinuity
in phase against the negative superhumps during the superoutburst
has become less marked.  The behavior in the amplitude is, however,
unusual in that the amplitude remarkably decreased around minimum of
the outburst, contrary to most "negatively superhumping" dwarf novae
(cf. http://adsabs.harvard.edu/abs/2010ARep...54....6P )