[en] The TRAPPIST-1 system is the first transiting planet system found orbiting an ultracool dwarf star[SUP] 1 [/SUP]. At least seven planets similar in radius to Earth were previously found to transit this host star[SUP] 2 [/SUP]. Subsequently, TRAPPIST-1 was observed as part of the K2 mission and, with these new data, we report the measurement of an 18.77 day orbital period for the outermost transiting planet, TRAPPIST-1 h, which was previously unconstrained. This value matches our theoretical expectations based on Laplace relations[SUP] 3 [/SUP] and places TRAPPIST-1 h as the seventh member of a complex chain, with three-body resonances linking every member. We find that TRAPPIST-1 h has a radius of 0.752 R [SUB]⊕[/SUB] and an equilibrium temperature of 173 K. We have also measured the rotational period of the star to be 3.3 days and detected a number of flares consistent with a low-activity, middle-aged, late M dwarf.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Luger, Rodrigo; Astronomy Department, University of Washington, Seattle, Washington 98195, USA. ; NASA Astrobiology Institute's Virtual Planetary Laboratory, Seattle, Washington 98195, USA.
Sestovic, Marko
Kruse, Ethan
Grimm, Simon L.; University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
Demory, Brice-Olivier
Agol, Eric; Astronomy Department, University of Washington, Seattle, Washington 98195, USA.
Bolmont, Emeline
Fabrycky, Daniel; Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA.
Silva Fernandes, Catarina ; Space Sciences, Technologies and Astrophysics Research Institute, Université de Liège, Allée du 6 Août 19C, B-4000 Liège, Belgium.
Van Grootel, Valérie ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Burgasser, Adam; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, California 92093, USA.
Gillon, Michaël ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Ingalls, James G.
Jehin, Emmanuel ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Raymond, Sean N.; Laboratoire d'Astrophysique de Bordeaux, Université Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France.
Selsis, Franck
Triaud, Amaury H. M. J.; Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK.
Barclay, Thomas; NASA Ames Research Center, Moffett Field, California 94043, USA. ; Bay Area Environmental Research Institute, 25 2nd Street Ste 209 Petaluma, California 94952, USA.
Barentsen, Geert; NASA Ames Research Center, Moffett Field, California 94043, USA.
Howell, Steve B.; NASA Ames Research Center, Moffett Field, California 94043, USA.
Delrez, Laetitia ; Space Sciences, Technologies and Astrophysics Research Institute, Université de Liège, Allée du 6 Août 19C, B-4000 Liège, Belgium. ; Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, UK.
de Wit, Julien
Foreman-Mackey, Daniel; Astronomy Department, University of Washington, Seattle, Washington 98195, USA.
Holdsworth, Daniel L.
Leconte, Jérémy; Laboratoire d'Astrophysique de Bordeaux, Université Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France.
Lederer, Susan; NASA Johnson Space Center, 2101 NASA Parkway, Houston, Texas 77058, USA.
Turbet, Martin
Almleaky, Yaseen; Space and Astronomy Department, Faculty of Science, King Abdulaziz University, 21589 Jeddah, Saudi Arabia. ; King Abdullah Centre for Crescent Observations and Astronomy, Makkah Clock, Mecca 24231, Saudia Arabia.
Benkhaldoun, Zouhair
Magain, Pierre ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Morris, Brett M.; Astronomy Department, University of Washington, Seattle, Washington 98195, USA.
Heng, Kevin; University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
Queloz, Didier; Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, UK. ; Observatoire de Genève, Université de Genève, 51 chemin des Maillettes, CH-1290 Sauverny, Switzerland.)
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