At least one in a dozen stars shows evidence of planetary ingestion

• 成果类型: Article
• 署名作者: Liu, Fan; Ting, Yuan-Sen; Yong, David; Bitsch, Bertram; Karakas, Amanda; Murphy, Michael T.; Joyce, Meridith; Dotter, Aaron; Dai, Fei
• 署名单位: Monash University; Swinburne University of Technology; Australian National University; Australian National University; University System of Ohio; Ohio State University; University System of Ohio; Ohio State University; Carnegie Institution for Science; Max Planck Society; University College Cork; HUN-REN; HUN-REN Research Centre for Astronomy & Earth Sciences; Konkoly Thege Miklos Astronomical Institute; Dartmouth College; California Institute of Technology; California Institute of Technology
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4063
• DOI: 10.1038/s41586-024-07091-y
• 发表日期: 2024-03-21
• 关键词: abundance; constraints; engulfment; signatures

摘要

Stellar chemical compositions can be altered by ingestion of planetary material1,2 and/or planet formation, which removes refractory material from the protostellar disk3,4. These 'planet signatures' appear as correlations between elemental abundance differences and the dust condensation temperature3,5,6. Detecting these planet signatures, however, is challenging owing to unknown occurrence rates, small amplitudes and heterogeneous star samples with large differences in stellar ages7,8. Therefore, stars born together (that is, co-natal) with identical compositions can facilitate the detection of planet signatures. Although previous spectroscopic studies have been limited to a small number of binary stars9-13, the Gaia satellite14 provides opportunities for detecting stellar chemical signatures of planets among co-moving pairs of stars confirmed to be co-natal15,16. Here we report high-precision chemical abundances for a homogeneous sample of ninety-one co-natal pairs of stars with a well defined selection function and identify at least seven instances of planetary ingestion, corresponding to an occurrence rate of eight per cent. An independent Bayesian indicator is deployed, which can effectively disentangle the planet signatures from other factors, such as random abundance variation and atomic diffusion17. Our study provides evidence of planet signatures and facilitates a deeper understanding of the star-planet-chemistry connection by providing observational constraints on the mechanisms of planet engulfment, formation and evolution. By analysing the chemical abundance differences of pairs of co-moving stars born together, it is found that about 8% show chemical signatures that indicate ingestion of planetary material.