[vsnet-campaign-dn 9197] OT J122221.6-311525: superhumps and interpretation

[Taichi Kato]

OT J122221.6-311525: superhumps and interpretation

   We have received further observations from Berto Monard,
William Stein and Kiyota-san.  All the data show superhumps
as described before.  The more recent period is 0.07692(4) d.

   We can now interpret that this object is an analogue
of OT J184228.1+483742 (cf. arXiv:1210.0678), which showed
only early superhumps and there was development of ordinary
superhumps during its second outburst.  We interpreted
this phenomenon as a result of a very slow growth of
the 3:1 resonance due to the low mass ratio (likely
a period bouncer).  The same would apply to OT J122221.6-311525.
The low-amplitude modulations during the initial outburst
may have been early superhumps, though we couldn't determine
the periodicity due to the short baseline.

   The second outburst started as an inside-out type outburst,
followed by a stagnation period (around Jan. 13).
Afteer this there was a precursor-like phase (Jan. 14-17)
when unstable superhumps appeared.  After this precursor
the object brightened (Jan. 19) and started to show
stable superhumps.