Validation of a Temperate Fourth Planet in the K2-133 Multi-planet System
arXiv:1905.05206 · doi:10.1093/mnras/stz1334
Abstract
We present follow-up observations of the K2-133 multi-planet 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 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 stars 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.
Accepted for publication in MNRAS
References in corpus (12)
- Most 1.6 Earth-Radius Planets are not Rocky
- How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
- Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
- A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
- 197 Candidates and 104 Validated Planets in K2's First Five Fields
- On Correlated-noise Analyses Applied To Exoplanet Light Curves
- Zodiacal Exoplanets in Time (ZEIT) V: A Uniform Search for Transiting Planets in Young Clusters Observed by K2
- On the protection of extrasolar Earth-like planets around K/M stars against galactic cosmic rays
- Three Small Super-Earths Transiting the nearby star GJ 9827
- Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
- The Transit Spectra of Earth and Jupiter
- Three small transiting planets around the M dwarf host star LP 358-499