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[vsnet-alert 940] V844 Her: unique short orbital period SU UMa star

V844 Her: unique short orbital period SU UMa star

    Recent reports [1,2] on V844 Her (=Var43 Her) confirm the star as
being an SU UMa star having one of the shortest superhump periods.

    A table of short Psh SU UMa stars (taken from [3]; stars with (*)
are newly added here):

            Psh                 Porb
---------------------------------------------------------
V485 Cen   0.0421              0.041          (*)
DI UMa     0.0555
V844 Her   0.056 +/- 0.001                    (*)
LL And     0.05700
WZ Sge     0.05714             0.05669
AL Com     0.0572              0.05666
SW UMa     0.0583              0.05681
HV Vir     0.05865             0.05799
WX Cet     0.05936             0.0582
RZ LMi     0.05946
T Leo      0.0602              0.05882
EG Cnc     0.06036             0.05821

    Aside from V485 Cen, all of these short Psh SU UMa stars are either
what is called WZ Sge-type dwarf novae and ER UMa-type (or RZ LMi-type)
dwarf novae.  The former category contains WZ Sge, AL Com, HV Vir, EG Cnc,
and related members LL And, SW UMa, WX Cet and T Leo.  The latter group
contains DI UMa and RZ LMi.  Which group will V844 Her belong to, or
comprise by itself a unique class?

    From available photometric materials ([4] and reports to VSNET),
bright (super) outbursts are separated by 220-230 days, without detectable
normal outbursts (despite the brightness of the object) so far.  Will it
mean V844 Her is a WZ Sge-type dwarf nova with a supercycle length of
220-230 (!) days?

Regards,
Taichi Kato

(please continue the discussion in vsnet-chat if necessary)

References:

[1] T. Vanmunster, CVC 141, or http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-alert/msg00935.html
[2] L. T. Jensen [vsnet-obs 5854] http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-obs/msg05854.html
[3] D. Nogami, S. Masuda, T. Kato 1997, PASP submitted
[4] S. V. Antipin 1996, IBVS 4360

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