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GO Com: updated superhump period (and super-QPOs?)
Dear Colleagues,
We have received further data from Nakajima-san, Nogami-san (Hida
Observatory, reported earlier), Tom Krajci. Sano-san also commnicated
the report of successful observation. From all the reported and analyzed
observations, we have obtained a refined superhump period of
0.06326(5) d. The superhump signal is very strong. In addition to these
superhumps, there is a hint of low-amplitude (~0.03 mag) qausi-periodic
oscillations with periods of 6-7 min. This feature was most prominent
in June 5 data. This appearance of QPOs dueing the early stage of
a superoutburst reminds us of "super-QPOs", which are long-period QPOs
with high coherence seen only during a limited stage of an superoutburst.
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/superqpo.html
Literature: Kato et al. (1992) PASJ 44, L215
Kato (2002) PASJ 54, 87
Although this phenomenon has a period similar to other QPOs in
(outbursting) dwarf novae, I consider that the mechanism of excitation
would be different, since the appearance of this phenomenon is closely
associated with a specific stage of a superoutburst. In any case,
the bright new, somewhat peculiar, SU UMa star GO Com would provide
deep insight into the physics of SU UMa-type stars, superhumps and
QPOs. Please continue observing this object as the top priority target
for the evening to midnight.
Regards,
Taichi Kato
VSNET Collaboration team
Return to the Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
