[vsnet-outburst 25972] BO Cet: standstill and now showing positive superhumps

Taichi Kato tkato at kusastro.kyoto-u.ac.jp
Wed Nov 4 14:37:35 JST 2020


BO Cet: standstill and now showing positive superhumps

   Josch Hambsch has been reporting observations
(IW And star).  The object had been in dwarf nova phase
until Oct. 20, but the subsequent outburst has not
faded for more than 14 days (persistent outburst?
or standstill).

   Surprisingly, it started to show large-amplitude
(0.20 mag) humps starting on Nov. 28.  The present
period is 0.1516(2) d, 8% longer than the orbital one.
If this is confirmed, this object is now in
superoutburst (!?) or, if prolonged, may be
permanent superhumps.  These superhumps have developed
in less than 10 days.  This evolution time prefers
SU UMa-type superhumps rather than permanent superhumps
(which are supposed to develop in long time in the novalike
state).  The object is brighter by 0.5 mag than in
past standstills.

   Anyway, more observations (also from different
observers) are needed.  The object is bright enough
(14 mag) and is ideally located on the equator.

   If confirmed, this object would be UGZ(IW)+UGSU!



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