[vsnet-chat 172] note on DM Lyr cycle lengths

[Taichi Kato <tkato>]

   Further to note on Daisaku Nogami's [vsnet-alert 761].

> Our 2.4hr photometry at Ouda Station revealed superhumps
> in DM Lyr on March 1, proving that the current outburst
> is a superoutburst.  The last superoutburst was caught
> in 1996 July.  This suggests the supercycle of ~230 days
> or its N-th.

   Previous outbursts of DM Lyr based on reports to VSNET (since 1994 June),
together with my own judgements based on outburst durations.

  1994 July 4-5    max 14.3  VAN,POY               normal
       Sep. 6-8    max 14.3  SNO,POY,Ths,Myy,Arm   normal
       Nov. 1-8    max 13.9  POY,Ths,Arm,SNO,BRO   super
  1995 Nov. 20-28  max 13.9  PIE,JEN,VAN,POY       super
  1996 July 7-18   max 13.7  POY,BMM,JSD,JEN,BRO,SQN,Kat,Ths,VAN,Oui,Oud
                                                   well-observed super
       Oct. 15     max 15.2? Myy (single obs.)
  1997 Feb. 26-    max 14.3  KNN,POY,HSG,Oud       super

   Three most recent superoutbursts were seperated almost equally by 230
days as Nogami-san mentioned.  The preceding cycle (~380 days) was, however,
a bit longer.  The typical cycle length of normal outbursts seems to be
around 60 days.

   Are these values rather normal for an SU UMa star? > Nogami-san

Regards,
Taichi Kato

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