The Chaotic History of the Retrograde Multi-planet System in K2-290A Driven by Distant Stars

dc.contributor.authorBest, Sergio
dc.contributor.authorPetrovich, Cristobal
dc.date.accessioned2025-01-20T22:00:53Z
dc.date.available2025-01-20T22:00:53Z
dc.date.issued2022
dc.description.abstractThe equator of star K2-290A was recently found to be inclined by 124 degrees +/- 6 degrees relative to the orbits of both its known transiting planets. The presence of a companion star B at similar to 100 au suggested that the birth protoplanetary disk could have tilted, thus providing an explanation for the peculiar retrograde state of this multi-planet system. In this work, we show that a primordial misalignment is not required and that the observed retrograde state is a natural consequence of the chaotic stellar obliquity evolution driven by a wider-orbit companion C at greater than or similar to 2000 au long after the disk disperses. The star C drives eccentricity and/or inclination oscillations on the inner binary orbit, leading to widespread chaos from the periodic resonance passages between the stellar spin and planetary secular modes. Based on a population synthesis study, we find that the observed stellar obliquity is reached in similar to 40%-70% of the systems, making this mechanism a robust outcome of the secular dynamics, regardless of the spin-down history of the central star. This work highlights the unusual role that very distant companions can have on the orbits of close-in planets and the host star's spin evolution, connecting four orders of magnitude in distance scale over billions of orbits. We finally comment on the application to other exoplanet systems, including multi-planet systems in wide binaries.
dc.fuente.origenWOS
dc.identifier.doi10.3847/2041-8213/ac49e9
dc.identifier.eissn2041-8213
dc.identifier.issn2041-8205
dc.identifier.urihttps://doi.org/10.3847/2041-8213/ac49e9
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/93758
dc.identifier.wosidWOS:000746156000001
dc.issue.numero1
dc.language.isoen
dc.revistaAstrophysical journal letters
dc.rightsacceso restringido
dc.subject.ods13 Climate Action
dc.subject.odspa13 Acción por el clima
dc.titleThe Chaotic History of the Retrograde Multi-planet System in K2-290A Driven by Distant Stars
dc.typeartículo
dc.volumen925
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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