[vsnet-alert 19304] NSV 1440: AM CVn-type superoutburst with early superhumps?

[Taichi Kato]

NSV 1440: AM CVn-type superoutburst with early superhumps?

   Berto Monard, Josch Hambsch and Lew Cook have reported
new observations.  As reported by the ASAS-SN team,
the object brightened again.  This brightening has also
been observed by CCD observers.  After this brightening,
the object showed more prominent superhumps with
a period of 0.025438(5) d.  Thanks to this identification,
now it became evident that the variations before the dip
were double-wave modulations, likely early superhumps.
By using the double period of 0.02523(2) d, the fractional
excess is 0.8%.  If the new variations are stage A superhumps,
thus excess corresponds to q=0.02.  Further observations
are strongly encouraged to see if the variations are
indeed stage A superhumps or not.  If the early variations
were indeed early superhumps, this is the first detection
in AM CVn-type objects.