GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

Authors: Kristine W. F. Lam, Szilárd Csizmadia, Nicola Astudillo-Defru, Xavier Bonfils, Davide Gandolfi, Sebastiano Padovan, Massimiliano Esposito, Coel Hellier, Teruyuki Hirano, John Livingston, Felipe Murgas, Alexis M. S. Smith, Karen A. Collins, Savita Mathur, Rafael A. Garcia, Steve B. Howell, Nuno C. Santos, Fei Dai, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Simon Albrecht, Jose M. Almenara, Etienne Artigau, Oscar Barragán, François Bouchy, Juan Cabrera, David Charbonneau, Priyanka Chaturvedi, Alexander Chaushev, Jessie L. Christiansen, William D. Cochran, José R. De Meideiros, Xavier Delfosse, Rodrigo F. Díaz, René Doyon, Philipp Eigmüller, Pedro Figueira, Thierry Forveille, Malcolm Fridlund, Guillaume Gaisné, Elisa Goffo, Iskra Georgieva, Sascha Grziwa, Eike Guenther, Artie P. Hatzes, Marshall C. Johnson, Petr Kabáth, Emil Knudstrup, Judith Korth, Pablo Lewin, Jack J. Lissauer, Christophe Lovis, Rafael Luque, Claudio Melo, Edward H. Morgan, Robert Morris, Michel Mayor, Norio Narita, Hannah L. M. Osborne, Enric Palle, Francesco Pepe, Carina M. Persson, Samuel N. Quinn, Heike Rauer, Seth Redfield, Joshua E. Schlieder, Damien Ségransan, Luisa M. Serrano, Jeffrey C. Smith, Ján Šubjak, Joseph D. Twicken, Stéphane Udry, Vincent Van Eylen, Michael Vezie

Published: 2021-12-02

DOI: 10.1126/science.aay3253

Source: Full article


Abstract

A nearby iron-rich sub-Earth planetThe mass and radius of an exoplanet determine its mean density, which provides information about the possible interior structure. Lamet al. have identified a planet on a 7.7-hour orbit around a nearby red dwarf star. The authors determined the planet’s radius from the transit, then used radial velocity observations to measure the mass. They found a sub-Earth–sized planet with a density almost equivalent to pure iron. Its high surface temperature is close to the vaporization point of iron, suggesting that it is the iron core of a planet that has lost its outer mantle. —KTS