$π$ Earth: a 3.14-day Earth-sized Planet from $\textit{K2}$'s Kitchen Served Warm by the SPECULOOS Team

Research output: Contribution to journalArticlepeer-review

Authors

  • Prajwal Niraula
  • Julien de Wit
  • Benjamin V. Rackham
  • Elsa Ducrot
  • Artem Burdanov
  • Ian J. M. Crossfield
  • Valerie Van Grootel
  • Catriona Murray
  • Lionel J. Garcia
  • Roi Alonso
  • Corey Beard
  • Yilen Gomez Maqueo Chew
  • Laetitia Delrez
  • Brice-Olivier Demory
  • Benjamin J. Fulton
  • Michael Gillon
  • Maximilian N. Gunther
  • Andrew W. Howard
  • Howard Issacson
  • Emmanuel Jehin
  • Peter P. Pedersen
  • Francisco J. Pozuelos
  • Didier Queloz
  • Rafael Rebolo-Lopez
  • Samantha Thompson

Colleges, School and Institutes

Abstract

We report on the discovery of a transiting Earth-sized (0.95$R_\oplus$) planet around an M3.5 dwarf star at 57$\,$pc, K2-315b. The planet has a period of $\sim$3.14 days, i.e. ${\sim}\pi$, with an instellation of 7.45$\,$S$_{\oplus}$. The detection was made using publicly available data from $\textit{K2}$'s Campaign 15. We observed three additional transits with SPECULOOS Southern and Northern Observatories, and a stellar spectrum from Keck/HIRES, which allowed us to validate the planetary nature of the signal. The confirmed planet is well suited for comparative terrestrial exoplanetology. While exoplanets transiting ultracool dwarfs present the best opportunity for atmospheric studies of terrestrial exoplanets with the $\textit{James Webb Space Telescope}$, those orbiting mid-M dwarfs within 100$\,$pc such as K2-315b will become increasingly accessible with the next generation of observatories.

Details

Original languageEnglish
JournalThe Astronomical Journal
Volume160
Issue number4
Publication statusAccepted/In press - 23 Jul 2020

Keywords

  • astro-ph.EP