[vsnet-campaign-dn 5173] 1RXS J023238.8-371812 superhumps update: marginally negative Pdot?

[Taichi Kato]

1RXS J023238.8-371812 superhumps update

  We have received new data from Peter Nelson.  The data on Oct 7
still showed regular superhumps.  The mean superhump period up to
now is 0.066191(6) d.  There is marginal indication of shortening
the superhump period with a provisional dotP/P value of -4(2)*10^(-5).
In most WZ Sge-type dwarf novae, period derivatives of ordinary
superhumps are close to zero or marginally positive.  If this
period shortening is confirmed and further continues, this would
be the most established negative Pdot in WZ Sge-type objects.
If this negative Pdot reflects a secondary similar to ordinary
SU UMa-type dwarf novae (and q similar to SU UMa-type dwarf novae
at this period), the long-lasting rapid fading stage before the dip
phenomenon will challenge theories of WZ Sge-type phenomenon.
Further continuous observations are thus strongly encouraged!