Transit Target Selection Using Reduced Proper Motions
Transit Target Selection Using Reduced Proper Motions
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DOI：
10.1086/346131
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发表时间：
2002-09
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影响因子：
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通讯作者：
A. Gould;C. Morgan
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文献类型：
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作者：
A. Gould;C. Morgan
在实地寻找凌日行星时，超过一半的调查恒星通常是巨星或其他太大而无法直接探测行星的恒星。对于明亮的 V ≲ 11 颗恒星的全天空搜索，该比例约为 90%。我们表明，通过分析污染物的简化自行（RPM），可以从样品中去除大部分污染物；巨人的转速比相同颜色的矮人低得多。我们使用依巴谷数据设计了 RPM 选择函数，该函数消除了大多数演化恒星，同时仅拒绝 9% 的可行凌日目标。我们的方法可以使用现有或即将发布的全天空数据应用于北半球 V < 12.5 的恒星和南半球 V < 12 的恒星。该方法的降解程度较弱，但效果很好。例如，在 V = 14 时，它仍然可以用来消除 V-I ~ 0.95 的红巨星，即红巨星团的蓝色边缘。
In searches for planetary transits in the field, well over half of the survey stars are typically giants or other stars that are too large to permit straightforward detection of planets. For all-sky searches of bright V ≲ 11 stars, the fraction is ~90%. We show that the great majority of these contaminants can be removed from the sample by analyzing their reduced proper motions (RPMs); giants have much lower RPMs than dwarfs of the same color. We use Hipparcos data to design a RPM selection function that eliminates most evolved stars, while rejecting only 9% of viable transit targets. Our method can be applied using existing or soon-to-be-released all-sky data to stars V < 12.5 in the northern hemisphere and V < 12 in the southern hemisphere. The method degrades at fainter magnitudes, but does so gracefully. For example, at V = 14 it can still be used to eliminate giants redward of V-I ~ 0.95, that is, the blue edge of the red giant clump.