V630 Cyg - new SU UMa star

Dear colleagues,

We, Ouda Team, have caught superhumps in V630 Cyg during the observation on 1996 Aug. 18. V630 Cyg is, thus, identified as a member of SU UMa stars. Our preliminary period analysis gives 0.079 (+- 0.003) d as the best estimated superhump period.

Thank all V630 Cyg observers for encouraging our observations!

Best regards,
Daisaku Nogami

Early alert on this outburst has been summarized by T. Vanmunster in CVC 103 as follows:

P. Skalak, Czech Republic, reports his visual detection of an outburst of the CVAP object V630 Cyg. He observed it on the evening of August 10, 1996 at mag. 14.5. An independent outburst detection has also been reported by Marc Biesmans, Essen, Belgium. Confirmative observations have been received from Tonny Vanmunster (CCD), Gary Poyner (visual) and D. Nogami (CCD).

1996 Aug 07.962 UT, [15.2  (G. Poyner, 0.40-m refl.);
     Aug 10.    UT,  14.5  (P. Skalak, seq: AAVSO);
     Aug 11.905 UT,  14.8  (T. Vanmunster, 0.25-m SCT, unfilt. CCD image);
     Aug 11.944 UT,  14.0  (G. Poyner);
     Aug 12.027 UT,  14.4  (M. Biesmans, 0.30-m SCT);

We again would like to stress that the classification of V630 Cyg as a SU UMa-type dwarf nova is still unsure. Therefore follow-up observations (in particular time-series CCD photometry in search of superhumps), are highly encouraged.

V630 Cyg was last seen in outburst on July 10, 1996 by E. Broens [CVC 99]. This was a normal, faint outburst [CVC 101].

SU UMa-type suspect

(vsnet-obs 1250, 1995 Sep. 29)

Although V630 Cyg has been a relatively well-known program star among variable star observers, this dwarf nova is still a "suspected" SU UMa-type dwarf nova. Some historical records ...

  max JD     mag   duration

  2437899   15.0   short
    37927   13.8   long (15d), probably a superoutburst
    37968   14.5   short
    38026   14.7
    38260   14.6   short
    38291   14.1   short
    38340   14.8
    38583   14.5

I would like to call observers' attention to monitor this star for superoutbursts, in order to confirm the long-suspected classification. Although outbursts of V630 Cyg are not rare, I think this star still deserves to be included in the alert program, especially for alerting superoutbursts.

Regards,
Taichi Kato