Constraining an exoplanet's magnetic field using star-planet interactions

• 成果类型: Article
• 署名作者: Revilla, D.; Amado, P. J.; Luque, R.; Schofer, P.; Lanza, A. F.; Binnenfeld, A.; Caballero, J. A.; Hatzes, A. P.; Henry, G. W.; Jeffers, S. V.; Kaur, S.; Palle, E.; Pena-Monino, L.; Perez-Torres, M.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Vigano, D.; Zapatero-Osorio, M. R.; Zucker, S.
• 署名单位: Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Instituto de Astrofisica de Andalucia (IAA); University of Chicago; Istituto Nazionale Astrofisica (INAF); Tel Aviv University; Tennessee State University; Institut d'Estudis Espacials de Catalunya (IEEC); Instituto de Astrofisica de Canarias; Universidad de la Laguna; Instituto de Astrofisica de Canarias; Ruprecht Karls University Heidelberg; University of Gottingen; Universitat de les Illes Balears; Tel Aviv University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adv3075
• 发表日期: 2026-07-23
• 页码: 403-407
• 关键词: CHROMOSPHERIC ACTIVITY; hot jupiters; IO

摘要

Theory predicts that a planet with a sufficiently strong magnetic field orbiting close to its host star could induce star-planet magnetic interactions. This is potentially observable as an optical or radio stellar activity signal synchronized with the planet's orbital period. We analyzed 18 years of high-resolution optical spectroscopy of GJ 436, a low-mass star orbited by a Neptune-sized exoplanet on a polar eccentric orbit. Stellar activity indicators show enhancements at a period corresponding to the exoplanet orbit, modulated by stellar rotation, and the star's 8-year magnetic cycle. We interpret this as a signal of star-planet magnetic interaction. Using a geometric model, we reproduced these periods if GJ 436 b has a magnetic field strength of 6 to 110 gauss.