K2-264: a transiting multiplanet system in the Praesepe open cluster
Journal article, 2019

Planet host stars with well-constrained ages provide a rare window to the time domain of planet formation and evolution. The NASA K2 mission has enabled the discovery of the vast majority of known planets transiting stars in clusters, providing a valuable sample of planets with known ages and radii. We present the discovery of two planets transiting K2-264, an M2 dwarf in the intermediate age (600-800 Myr) Praesepe open cluster (also known as the Beehive Cluster, M44, or NGC 2632), which was observed by K2 during Campaign 16. The planets have orbital periods of 5.8 and 19.7 d, and radii of 2.2 ± 0.2 and 2.7 ± 0.2R⊕, respectively, and their equilibrium temperatures are 496 ± 10 and 331 ± 7 K, making this a system of two warm sub-Neptunes. When placed in the context of known planets orbiting field stars of similar mass to K2-264, these planets do not appear to have significantly inflated radii, as has previously been noted for some cluster planets. As the second known system of multiple planets transiting a star in a cluster, K2-264 should be valuable for testing theories of photoevaporation in systems of multiple planets. Follow-up observations with current near-infrared (NIR) spectrographs could yield planet mass measurements, which would provide information about the mean densities and compositions of small planets soon after photoevaporation is expected to have finished. Follow-up NIR transit observations using Spitzer or large ground-based telescopes could yield improved radius estimates, further enhancing the characterization of these interesting planets.

techniques: photometric

planets and satellites: detection

techniques: high angular resolution

Author

J. Livingston

University of Tokyo

JSPS

F. Dai

Massachusetts Institute of Technology (MIT)

Princeton University

T. Hirano

Tokyo Institute of Technology

D. Gandolfi

University of Turin

A. A. Trani

University of Tokyo

JSPS

G. Nowak

University of La Laguna

Instituto Astrofisico de Canarias

W. D. Cochran

The University of Texas at Austin

M. Endl

The University of Texas at Austin

S. Albrecht

Aarhus University

O. Barragan

University of Turin

J. Cabrera

German Aerospace Center (DLR)

Sz. Csizmadia

German Aerospace Center (DLR)

J. P. de Leon

University of Tokyo

H. Deeg

Instituto Astrofisico de Canarias

University of La Laguna

Ph Eigmüller

German Aerospace Center (DLR)

Technische Universität Berlin

A. Erikson

German Aerospace Center (DLR)

Malcolm Fridlund

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Leiden University

A. Fukui

Instituto Astrofisico de Canarias

National Astronomical Observatory of Japan

S. Grziwa

University of Cologne

E. W. Guenther

Thüringer Landessternwarte Tautenburg

A. P. Hatzes

Thüringer Landessternwarte Tautenburg

J. Korth

University of Cologne

M. Kuzuhara

National Astronomical Observatory of Japan

National Institutes of Natural Sciences

P. Montañes

Instituto Astrofisico de Canarias

University of La Laguna

N. Narita

National Institutes of Natural Sciences

University of Tokyo

National Astronomical Observatory of Japan

Instituto Astrofisico de Canarias

D. Nespral

Instituto Astrofisico de Canarias

University of La Laguna

E. Palle

Instituto Astrofisico de Canarias

University of La Laguna

M. Pätzold

University of Cologne

Carina Persson

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

J. Prieto-Arranz

University of La Laguna

Instituto Astrofisico de Canarias

H. Rauer

Technische Universität Berlin

German Aerospace Center (DLR)

Freie Universität Berlin

M. Tamura

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

University of Tokyo

V. Van Eylen

Leiden University

J. N. Winn

Princeton University

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 484 1 8-18

Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects

Swedish National Space Board, 2017-01-01 -- 2022-12-31.

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

Infrastructure

Onsala Space Observatory

DOI

10.1093/mnras/sty3464

More information

Latest update

7/16/2019