Validation of a Temperate Fourth Planet in the K2-133 Multi-planet System

R. Wells, K. Poppenhaeger, C. A. Watson

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)
113 Downloads (Pure)


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 1.73_{-0.13}^{+0.14} 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.
Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society, Advance Access
Publication statusPublished - 01 May 2019


  • techniques: photometric
  • planets and satellites: general
  • stars: low-mass
  • stars: individual: LP 358-499
  • stars: individual: K2-133


Dive into the research topics of 'Validation of a Temperate Fourth Planet in the K2-133 Multi-planet System'. Together they form a unique fingerprint.

Cite this