激变变星V1159 Ori和BZ UMa的测光研究

The Photometry of Cataclysmic Variable V1159 Ori and BZ UMa

V1159 Ori是SU UMa型中ER UMa亚型激变变星,BZ UMa介于UGem型和WZ Sge型之间,但又具有SU UMa的周期特征,存在争议.在2008年2月24日和25日,用云南天文台1米RCC(Ritchey-Chretien-Coude)望远镜对两者的测光观测显示:V1159 Ori在正常爆发的下降阶段存在superhump,这为superhump现象普遍存在于ER UMa型星中提供了观测证据;BZ UMa观测时处于爆发极大,并未观测到确凿的superhump周期,而AAVSO(American Association of Variable Star Observers)近年的BZ UMa观测亦从未发现明确的superhump;两者均表明BZ UMa可能并非SUUMa型星.基于星等变化幅度考虑,BZ UMa较WZ Sge更为接近.

Photometry of the cataclysmic variables Vl159 Ori and BZ UMa are conducted with the lm RCC optical telescope in Yunnan Astronomical Observatory from Feb. 24th to 25th, 2008. The light curves of Vl159 Ori denote superhumps during the fading period of a normal outburst. Previous observations revealed superhumps in ER UMa during normal outbursts, convincing that it is universal in ER UMa class. This photometry helps to assure superhumps＇ presence in ordinary outbursts of ER UMa class. As to the controversial BZ UMa, whose orbital period is below the period gap of SU Uma, no apparent observable superhumps are detected in either previous observations or that of this time. Therefore, it is more likely to side with U Gem class or WZ Sge class, with the latter of more likelihood.