Cold giant discoveries from a joint radial-velocity and astrometry framework
Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales（智利道格拉斯·波特莱斯大学工程与科学学院天体物理研究所）；Centro de Astrofísica y Tecnologías Afines (CATA)（天文及相关技术中心）；State Key Laboratory of Dark Matter Physics, Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院，桐溪研究院暗物质物理国家重点实验室）；Institute of Physics, Laboratory of Astrophysics, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院物理研究所天体物理实验室）
Pablo A. Peña, James S. Jenkins, Fabo Feng, Douglas R. Alves, Florence de Almeida, Frédéric Dux, Guang-Yao Xiao, Joanne M. Rojas M., Jose I. Vines, Rafael I. Ru… 展开作者
Pablo A. Peña, James S. Jenkins, Fabo Feng, Douglas R. Alves, Florence de Almeida, Frédéric Dux, Guang-Yao Xiao, Joanne M. Rojas M., Jose I. Vines, Rafael I. Rubenstein, R. Ramírez Reyes, Suman Saha, Connor J. Cheverall, Matías R. Díaz
The population of long-period giant planets shapes planetary system architectures and formation pathways, but these cold Jupiters remain relatively unexplored. Radial velocity (RV) surveys lose sensitivity at multi-AU separations, while transit surveys have poor detection probability at long periods. Absolute astrometry from the Hipparcos and Gaia missions offer an additional source for stellar motion that can break the orbital inclination degeneracy and strengthen detection confidence. This is especially timely ahead Gaia DR4/DR5, expected to enable routine astrometric vetting and true-mass measurements for long-period RV planets. Extending the Chile-Hertfordshire ExoPlanet Survey (CHEPS) by combining RVs spanning up to 16 years with absolute astrometry, we search for and characterise cold giants around metal-rich FGK stars. We upgrade the EMPEROR framework, incorporating astrometric differencing to jointly fit RVs and astrometry for five CHEPS targets, performing Bayesian model comparison and quantify the astrometric contribution. Our analysis characterises orbital parameters for two known planets in HIP 21850 and detects five new: a warm Jupiter--HIP 10090c, orbital period $P=321.8 \pm 0.5$ d and mass $M=0.85 \pm 0.08$ $M_J$, and four Jupiter analogues--HIP 8923b, with $P=14.1 \pm 0.06$ yr and $M=9.98\pm 0.47 M_J$, HIP 10090b with $P=8.1\pm 0.3$ yr and $M=3.87\pm 0.63$ $M_J$, HIP 39330b with $P=12.7\pm 0.7$ yr and $M=1.68\pm 0.15$ $M_J$, and HIP 98599b with $P=7.3\pm 0.1$ yr and $M=6.85\pm 0.16$ $M_J$. Adding astrometry reduces period and mass uncertainties by factors between 3 and 10 and increases the Bayes factor by up to 60. The synergy of long-baseline RVs and absolute astrometry provides a robust pathway to discover and characterise cold giant planets. Our results demonstrate that astrometry meaningfully improves detection confidence and converts minimum masses into true masses.
Detection of four cold Jupiters through combined analyses of radial velocity and astrometry data
State Key Laboratory of Dark Matter Physics, Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（暗物质物理国家重点实验室、李政道研究所与物理天文学院，上海交通大学）；Earth and Planets Laboratory, Carnegie Institution for Science（地球与行星实验室，卡内基科学机构）；Observatories of the Carnegie Institution for Science（卡内基科学机构天文台）
A Planetary Illusion's Funeral: Non-detection of a Gaia DR3 Exoplanet Candidate, and the Role of Intermediate-precision Radial Velocities in Gaia Exoplanet Follow-up
Centre for Astrophysics, University of Southern Queensland（南昆士兰大学天体物理中心）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）；Center for Astrophysics, Harvard & Smithsonian（哈佛-史密森尼天体物理中心）
Unraveling the Brown Dwarf Desert: Four New Discoveries and a Unifying, Period-Coded Picture
Czech Academy of Sciences（捷克科学院）；Harvard & Smithsonian（哈佛-史密森天体物理中心）；Universidad Adolfo Ibáñez（阿道夫·伊巴涅斯大学）；Millennium Institute for Astrophysics（天体物理学千年研究所）；Astronomical Institute of Charles University（查理大学天文研究所）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；The Ohio State University（俄亥俄州立大学）；University of Leicester（莱斯特大学）；Massachusetts Institute of Technology（麻省理工学院）；Sofia University “St Kliment Ohridski”（索非亚“圣克利门特·奥赫里德斯基”大学）
Worlds Next Door. IV. Mapping the Late Stages of Giant Planet Evolution with a Precise Dynamical Mass and Luminosity for $ε$ Ind Ab
Cahill Center for Astronomy and Astrophysics, California Institute of Technology（加州理工学院卡希尔天文学与天体物理学中心）；NRC Herzberg Astronomy and Astrophysics（NRC赫茨伯格天文学与天体物理学研究所）；Department of Astronomy, University of Texas at Austin（德克萨斯大学奥斯汀分校天文学系）；Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles（加利福尼亚大学洛杉矶分校地球、行星与空间科学系）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）
利用JWST近红外和中红外成像以及三十年径向速度与天体测量数据，精确测定冷气态巨行星ε Ind Ab的动力学质量（6.5 M_Jup）并构建其4-25 μm光谱能量分布，验证了巨行星质量-金属丰度关系，并发现其云层特征与演化模型预测高度吻合。
ELemental abundances of Planets and brown dwarfs Imaged around Stars (ELPIS): I. Potential Metal Enrichment of the Exoplanet AF Lep b and a Novel Retrieval Approach for Cloudy Self-luminous Atmospheres
该研究通过新型温度梯度约束反演方法，分析直接成像系外行星 AF Lep b 的大气，发现其金属增丰（[Fe/H] > 1.0 dex）并存在硅酸盐云，为行星形成与演化提供新见解。
