[vsnet-alert 15639] CSS J174033.5+414756: updated period of early superhumps, spectrum

[Taichi Kato]

CSS J174033.5+414756: updated period of early superhumps, spectrum

   Pavol A. Dubovsky and Colin Littlefield have reported
further observations (Dubovsky's first observations was
earlier than Littlefield's one).  We now have a much refined
period of early superhumps: 0.04503(1) d.
The profile is asymmetric double humps and the full amplitude
is about 0.02 mag (mean).

   According to ATEL 4999, ASAS-SN team detected this object
on April 19 at V=12.7.  The object has been confirmed to be
hydrogen-rich, and it is not an AM CVn-type object.
I see that He II 4686 is in emission and helium is enhanced
as seen from the strength of He I lines.

   The object is likely to have an evolved core in
the secondary (pre-AM CVn-type?), and measurement of superhump
excess is extremely important.  Please follow this object
as continuously as possible to detect stage A and B superhumps
and see how they emerge.