EMERGING TRENDS IN A PERIOD–RADIUS DISTRIBUTION OF CLOSE-IN PLANETS
EMERGING TRENDS IN A PERIOD–RADIUS DISTRIBUTION OF CLOSE-IN PLANETS
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DOI：
10.1088/0004-637x/763/1/12
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发表时间：
2012-11
期刊：
影响因子：
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通讯作者：
C. Beaugé;D. Nesvorný
中科院分区：
文献类型：
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作者：
C. Beaugé;D. Nesvorný
我们分析了太阳系外行星(包括已确认的和开普勒候选行星)的轨道周期P和行星半径R的分布。在已确认的行星中，我们找到了令人信服的证据，证明3R⊕<；R<；10R⊕的天体很少，其中R⊕是地球的半径，P<；2-3天。我们已将这一地区命名为亚木星潘帕斯。在多行星开普勒候选行星中也检测到了同样的趋势。尽管大约有16颗开普勒单行星候选者居住在这片潘帕斯，但至少有7颗是可能的假阳性(FP)。最近的研究表明，如果FP的比例高于10%，最后一个数字可能会显著高于10%。在本文的第二部分中，我们根据恒星的金属度分析了行星在(P，R)平面上的分布。我们发现了两个有趣的趋势：(1)贫金属星中缺少轨道周期为P<；5天的小行星(R<；4R⊕)；(2)也在贫金属星周围，缺乏具有P<；100天轨道周期的亚木星行星(4R⊕<；R<；8R⊕)。尽管所有这些趋势都是初步的，但它们似乎具有统计意义，值得进一步研究。如果得到证实，它们可能代表着对行星形成和动力学演化理论的重要限制。
We analyze the distribution of extrasolar planets (both confirmed and Kepler candidates) according to their orbital periods P and planetary radii R. Among confirmed planets, we find compelling evidence for a paucity of bodies with 3 R⊕ < R < 10 R⊕, where R⊕ is Earth's radius and P < 2–3 days. We have christened this region a sub-Jovian Pampas. The same trend is detected in multiplanet Kepler candidates. Although approximately 16 Kepler single-planet candidates inhabit this Pampas, at least 7 are probable false positives (FPs). This last number could be significantly higher if the ratio of FPs is higher than 10%, as suggested by recent studies. In a second part of the paper we analyze the distribution of planets in the (P, R) plane according to stellar metallicities. We find two interesting trends: (1) a lack of small planets (R < 4 R⊕) with orbital periods P < 5 days in metal-poor stars and (2) a paucity of sub-Jovian planets (4 R⊕ < R < 8 R⊕) with P < 100 days, also around metal-poor stars. Although all these trends are preliminary, they appear statistically significant and deserve further scrutiny. If confirmed, they could represent important constraints on theories of planetary formation and dynamical evolution.