Validation of a temperate fourth planet in the K2-133 multiplanet system
- We present follow-up observations of the K2-133 multiplanet system. Previously, we announced that K2-133 contained three super-Earths orbiting an M1.5V host star – with tentative evidence of a fourth outer-planet orbiting at the edge of the temperate zone. Here, we report on the validation of the presence of the fourth planet, determining a radius of 1.73+0.14−0.13 R⊕. The four planets span the radius gap of the exoplanet population, meaning further follow-up would be worthwhile to obtain masses and test theories of the origin of the gap. In particular, the trend of increasing planetary radius with decreasing incident flux in the K2-133 system supports the claim that the gap is caused by photo-evaporation of exoplanet atmospheres. Finally, we note that K2-133 e orbits on the edge of the star's temperate zone, and that our radius measurement allows for the possibility that this is a rocky world. Additional mass measurements are required to confirm or refute this scenario.
Author details: | Robert WellsORCiD, Katja PoppenhägerORCiDGND, C. A. Watson |
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DOI: | https://doi.org/10.1093/mnras/stz1334 |
ISSN: | 0035-8711 |
ISSN: | 1365-2966 |
Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
Publisher: | Oxford Univ. Press |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Date of first publication: | 2019/05/16 |
Publication year: | 2019 |
Release date: | 2020/12/10 |
Tag: | planets and satellites: general; stars: individual: K2-133; stars: individual: LP 358-499; stars: low-mass; techniques: photometric |
Volume: | 487 |
Issue: | 2 |
Number of pages: | 9 |
First page: | 1865 |
Last Page: | 1873 |
Funding institution: | National Aeronautics and Space Administration under the Exoplanet Exploration Program; Northern Ireland Department for Education; Leibniz Association through its 2019 Leibniz Competition Program; Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC) [ST/P000312/1] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Green Open-Access |