Abstract

The reduction of all the available photometry for the Cepheid EV Aql has allowed its \(O-C\) diagram spanning a time interval of 130 years to be constructed. This has made it possible to calculate the rate of evolutionary decrease in the period, \(dP/dt=-33.2({\pm}{6.9})\) s yr\({}^{-1}\), in agreement with the results of model calculations for the second crossing of the instability strip. The pulsation stability test proposed by Lombard and Koen has confirmed that the decrease in the period is real.

中文翻译：

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寻找古典造父变星EV Aql时期的进化变化

摘要

造父变星EV Aql的所有可用光度法的减少，使得它的\（OC \）图跨越了130年的时间间隔得以构建。这使得能够计算在期间进化的减少速度，\（DP / DT = -33.2（{\ PM} {6.9}）\）小号年\（{} ^ { - 1} \） ，在与不稳定带第二次穿越的模型计算结果一致。Lombard和Koen提出的脉动稳定性测试已经证实，周期的减小是真实的。