开普勒-47双星系统的宜居带

The Habitable Zone of Kepler-47 Binary System

摘要: 一颗系外行星上如果存在生命，它需要位于其寄主恒星的宜居带中。本文考虑了恒星有效温度对宜居带的影响，给出了双星宜居带的内、外边界的距离满足的方程。我们用数值法求出了开普勒-47双星系统的宜居带，其内、外边界的平均半径分别为0.77761和1.55287AU。开普勒-47内行星距离双星比较近，不在宜居带中。开普勒-47外行星围绕双星公转的轨道可能是一个椭率为0.411的椭圆，它的远日点处在宜居带中，而近日点不在宜居带中。在一个公转周期内，它有237.837至239.056天的时间处在宜居带中，而有64.102至65.321天的时间不在宜居带中。

Abstract: Provided that there are lives living on an exoplanet, it must be located in the habitable zone of its host star. Considering the effects of stellar effective temperature on habitable zone, we give the distance equations on the inside and the outside boundary of binary’s habitable zone. Using the numerical methods, we obtain the habitable zone of the Kepler-47 binary system. The average distances on the inside and the outside boundary are 0.77761 and 1.55287 AU, respectively. The distance of the Kepler-47 inner planet is too small to be within the habitable zone. The orbit of the Kepler-47 outer planet may be an ellipse. Its eccentricity is 0.411; its aphelion is within the habitable zone, and its perihelion is not within the habitable zone. In an orbital period, there are 237.837 - 239.056 days that the Kepler-47 outer planet is within the habitable zone and there are 64.102 - 65.321 days that it is not within the habitable zone.