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(1993 Feb. 21)
subject: 1215-17 Crv, CC Cnc
Results of CCD observations
1215-17 Crv
V=17.2 at Feb 20.768 UT
slightly brighter than that (V=18.0) obtained in quiescence
(cf. THE ASTRONOMER Electronic Circular No 711)
CC Cnc
1) Averaged magnitudes
Using GSC V=11.7 mag star as the local standard, following averaged
magenitudes are obtained: V=13.7 on Feb. 19 and V=13.9 on Feb. 20.
The star faded by 0.8 magnitude in five days, in good agreement with
decline rateS of other SU UMa stars during superoutbursts.
2) Detection of superhumps
Although the sky was covered with thin cloud, reliable photometry
was obtained on Feb. 20. The light curve showed humps with an amplitude
of 0.20 magnitude and the hump maxima at 20.642 and 20.718 UT.
The rise was steeper than the decline, and neither secondary humps nor
eclipses were detected.
3) Superhump period
Analysis of the light curve on Feb. 20 yields the best superhump period
of 0.076 +/- 0.005 day. Connecting this to the fragmentary observations
(but similar light variation was already perceived) on Feb. 19,
we can get the best estimate of the period of 0.0761 day. One-day alias
of 0.0709 day has less possibility.
Regards,
Taichi Kato
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
