开普勒已经确定了600多个多行星系统，其中许多行星的轨道距离小于水星-与太阳系完全不同。由于这些系统可能很难用核心吸积和盘迁移的范式来解释，因此有人认为它们是在具有高固体表面密度的原行星盘内原位形成的。巨行星的出现和恒星金属丰度之间的紧密联系被认为与富含金属的恒星周围的圆盘中固体表面密度的增强有关，因此巨行星的存在可以是高固体表面密度圆盘中行星形成的可检测迹象。我制定的定量预测的频率长周期巨行星在这些原位模型的行星形成通过翻译提出的增加磁盘质量到一个等效的金属丰度增强。重新推导了巨行星产状与金属丰度的比例关系为P_gp = 0.05_{-0.02}^{+0.02} x 10^{（2.1 +/- 0.4）[M/H]} = 0.08_{-0.03}^{+0.02} x 10^{（2.3 +/- 0.4）[Fe/H]}，并表明在最小质量太阳系外星云假设和观测上限之间存在着巨大行星的频率。这一事实表明，仅凭高质量盘无法解释近距离开普勒多行星系统的观测特性，迁移仍然是其形成的必要因素。更投机的是，我结合最近公布的小行星发生率的巨行星发生率的金属丰度标度来估计银河系中太阳系类似物的数量。我发现在银河系中可能有4 x 10^6个真正的太阳系类似物，其中一颗FGK恒星在宜居带中拥有一颗类地行星和一颗长周期巨行星伴星。
英文摘要：
Kepler has identified over 600 multiplanet systems, many of which have several planets with orbital distances smaller than that of Mercury -- quite different from the Solar System. Because these systems may be difficult to explain in the paradigm of core accretion and disk migration, it has been suggested that they formed in situ within protoplanetary disks with high solid surface densities. The strong connection between giant planet occurrence and stellar metallicity is thought to be linked to enhanced solid surface densities in disks around metal-rich stars, so the presence of a giant planet can be a detectable sign of planet formation in a high solid surface density disk. I formulate quantitative predictions for the frequency of long-period giant planets in these in situ models of planet formation by translating the proposed increase in disk mass into an equivalent metallicity enhancement. I rederive the scaling of giant planet occurrence with metallicity as P_gp = 0.05_{-0.02}^{+0.02} x 10^{(2.1 +/- 0.4) [M/H]} = 0.08_{-0.03}^{+0.02} x 10^{(2.3 +/- 0.4) [Fe/H]} and show that there is significant tension between the frequency of giant planets suggested by the minimum mass extrasolar nebula scenario and the observational upper limits. This fact suggests that high-mass disks alone cannot explain the observed properties of the close-in Kepler multiplanet systems and that migration is still a necessary contributor to their formation. More speculatively, I combine the metallicity scaling of giant planet occurrence with recently published small planet occurrence rates to estimate the number of Solar System analogs in the Galaxy. I find that in the Milky Way there are perhaps 4 x 10^6 true Solar System analogs with an FGK star hosting both a terrestrial planet in the habitable zone and a long-period giant planet companion.
Orbital stability of compact three-planet systems III. The role of three-body resonances
Dipartimento di Fisica e Astronomia, Università di Bologna（博洛尼亚大学物理与天文学系）；Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所与恒星与行星形成中心）；Space Science & Astrobiology Division, MS 245-3, NASA Ames Research Center（NASA艾姆斯研究中心空间科学与天体生物学部）
Atmospheric Circulation of High-Obliquity Mini-Neptunes
Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所）；School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）；State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（上海交通大学暗物质重点实验室）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体科学系）；Canadian Institute for Theoretical Astrophysics（加拿大理论天体物理研究所）
