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Re: [vsnet-alert 7655] EU CMa: possible superhumps Dear Colleagues, We have receeived an image and a set of time-series observations from Berto Monard. The image is shown on the following page. http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/eucma.html Astrometry and the identification are being examined by Yamaoka-san: there may be inconsistencies between the catalogs, which will be reviewed in detail by Yamaoka-san. The light curve by Berto Monard looks rather flat, with a slow mean decline rate of 0.2 mag/day. A closer look at the Kyoto data seems to suggest that the possible superhump detection announced in [vsnet-alert 7655] would have been spurious, possibly caused by occasional saturation of the comparison star. Refined photometry using a fainter comparison star is consistent with the result by Berto Monard, although a 0.1-mag variation is not yet excluded. We thereby cancel the description in [vsnet-alert 7655]. The mean decline rate, however, is inconsistent with a normal outburst of an SU UMa-type dwarf nova. The data more suggest an SS Cyg-type dwarf nova, although the full amplitude of the outburst may be incompatible with this classification. It is still possible that true superhumps need to have additional time to develop. Please keep watching the object until a more defitinte conclusion is reached. Regards, Taichi Kato VSNET Collaboration team
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
