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arXiv · 2112.01309

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

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
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Abstract

Ultra-short-period (USP) exoplanets have orbital periods shorter than one day. Precise masses and radii of USPs could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude = 10.2), nearby, red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of $0.718 \pm 0.054$ Earth-radii, a mass of $0.546 \pm 0.078$ Earth-masses, making it a sub-Earth. The corresponding bulk density is $8.106 \pm 2.165$ g cm$^-3$, close to that of iron. An interior structure model predicts the planet has an iron core radius fraction of $86 \pm 5\%$, similar to Mercury's interior.

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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. 2021-12-02. GJ 367b: A dense ultra-short period sub-Earth planet transiting a nearby red dwarf star. https://doi.org/10.1126/science.aay3253

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