摘要
对非径向脉动δScuti(盾牌座δ)型变星4CVn的最新光电测光观测,证实了其振幅和周期的长期缓慢变化.两种多重频率分析方法都一致确认出已知7个频率中的5个(f1,f2,f3,f5,f7).观测还发现三个可疑频率.目前主频的振幅和十几年前的一样,基本保持不变,可能正处于向最大振幅变化的增加阶段或者处于刚过极大的下降段.其它四个频率的振幅都不同程度地变大.f2,f3和f5的振幅增幅分别为63%,25%和120%,尤其是f7,从上次的0变为0.009mag.频率分析显示除主频f1几乎未变外,其它频率缓慢变化:f2和f7约减小0.08%;f3减小0.14%;f5增加0.03%.用Blazhko效应和不同非径向脉动模式之间的共振解释振幅和周期变化的合理性,尚需进一步从观测上检验.
New photoelectric photometry of the δ Scuti variable 4 CVn reveals long term slow variations of multimode pulsational frequencies and their amplitudes. We have confirmed 5(f 1, f 2, f 3, f 5, f 7) of the 7 frequencies identified in the literature. Besides presenting the long term variations of the different amplitudes, we have found three new suspected frequencies in the new data.Although Blazhko effect and mode resonance along with its coupling between different nonradial modes through interaction can be reasonably used to explain the observed changes of periods and amplitudes, it should be carefully checked and analyzed before RR Lyr like light curve shape and new pulsation modes can be established with certainty.
基金
国家自然科学基金