标题： 星际光线的偏振：未解析的椭圆轨道扁球状系外行星引起的 显示英文标题

标题： Polarization of Starlight by Unresolved and Oblate Extra-solar Planet in Elliptical Orbit

摘要： 我们计算了来自可能无法在空间上分辨的恒星的线性偏振度，这些恒星带有行星。 我们假设行星大气中的水和硅酸盐颗粒发生单次散射。 包括行星反射偏振辐射被恒星非偏振辐射稀释以及行星扁率及其椭圆轨道的影响。 我们采用化学平衡模型来估算水和硅酸盐冷凝物的数量密度，并计算星光在R波段的线性偏振度，作为以下参数的函数：（1）冷凝物平均尺寸，（2）行星扁率，（3）倾角，（4）相角，（5）轨道偏心率e，以及（6）近日点通过的历元。 我们表明，在考虑椭圆轨道时，所有倾角下的偏振轮廓都会显著变化，并且偏振度在近日点通过的历元达到峰值。 我们预测，如果行星大气光学厚度较小，冷凝物的平均尺寸不超过几微米，并且行星的扁率与木星相当，则可能会产生可检测到的线性偏振量。 显示英文摘要

摘要： We calculate the degree of linear polarization of radiation from stars having planets that may not be resolved spatially. We assume single scattering by water and silicate particulates in the planetary atmosphere. The dilution of the reflected polarized radiation of the planet by the unpolarized stellar radiation and the effect of oblateness of the planet as well as its elliptical orbit are included. We employ a chemical equilibrium model to estimate the number density of water and silicate condensates and calculate the degree of linear polarization at R band of starlight as a function of (1) mean size of condensates, (2) planetary oblateness, (3) inclination angle, (4) phase angle, (5) orbital eccentricity e and (6) the epoch of periastron passage. We show that the polarization profile alters significantly at all inclination angles when elliptical orbit is considered and the degree of polarization peaks at the epoch of periastron passage. We predict that detectable amount of linear polarization may arise if the planetary atmosphere is optically thin, the mean size of the condensates is not greater than a few microns and the oblateness of the planet is as high as that of Jupiter.