{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/a-seven-planet-resonant-chain-in-trappist-1","title":"A seven-planet resonant chain in TRAPPIST-1","arxiv_id":"1703.04166","date":"2017-03-12","proceeding":null,"authors":["Rodrigo Luger","Marko Sestovic","Ethan Kruse","Simon L. Grimm","Brice-Olivier Demory","Eric Agol","Emeline Bolmont","Daniel Fabrycky","Catarina S. Fernandes","Valérie Van Grootel","Adam Burgasser","Michaël Gillon","James G. Ingalls","Emmanuël Jehin","Sean N. Raymond","Franck Selsis","Amaury H. M. J. Triaud","Thomas Barclay","Geert Barentsen","Steve B. Howell","Laetitia Delrez","Julien de Wit","Daniel Foreman-Mackey","Daniel L. Holdsworth","Jérémy Leconte","Susan Lederer","Martin Turbet","Yaseen Almleaky","Zouhair Benkhaldoun","Pierre Magain","Brett Morris","Kevin Heng","Didier Queloz"],"abstract":"The TRAPPIST-1 system is the first transiting planet system found orbiting an ultra-cool dwarf star. At least seven planets similar to Earth in radius and in mass were previously found to transit this host star. Subsequently, TRAPPIST-1 was observed as part of the K2 mission and, with these new data, we report the measurement of an 18.77 d orbital period for the outermost planet, TRAPPIST-1h, which was unconstrained until now. This value matches our theoretical expectations based on Laplace relations and places TRAPPIST-1h as the seventh member of a complex chain, with three-body resonances linking every member. We find that TRAPPIST-1h has a radius of 0.727 Earth radii and an equilibrium temperature of 173 K. We have also measured the rotational period of the star at 3.3 d and detected a number of flares consistent with a low-activity, middle-aged, late M dwarf.","url_abs":"http://arxiv.org/abs/1703.04166v2","url_pdf":"http://arxiv.org/pdf/1703.04166v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"a-seven-planet-resonant-chain-in-trappist-1","repo_url":"https://github.com/rodluger/trappist1","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}