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(1993 Mar. 6)
subject: CY UMa
*** Detection of superhumps in CY UMa
-- A new SU UMa star with a definitely determined period.
Reduction of V-band CCD observations on Mar. 5 yields following results.
1) Mean magnitude
The star declined from +0.3 to +0.4 in nine hours (comarison: GSC
105705.38 +493730.4 (2000.0) V=12.9). The star may have started its
final decline from the present superoutburst.
2) Detection of superhumps
The hump structures have mean amplitudes of 0.11 mag in V. The rises
are steeper than the declines as in usual superhumps. The eclipses
are not detected.
3) The superhump period
The maxima of superhump occurred at 5.476, 5.546, 5.620, 5.690, 5.763,
and 5.838 UT. The times are well expressed by the following formula.
Max UT = Mar. 5.475 + 0.0723 E
The baseline of the observation was long enough, therefore the period
will be accurate to at least 0.5%.
The period is not in agreement with the previously published one (Var.
Star Bull.) which was based on visual observations only.
Regards,
Taichi Kato
Return to the Powerful Daisaku
vsnet-adm@kusastro.kyoto-u.ac.jp
