Exoplanets & Exomoons

A Terrestrial Planet Candidate in a Temperate Orbit Around Proxima Centauri

By Keith Cowing
Press Release
September 12, 2016
Filed under
A Terrestrial Planet Candidate in a Temperate Orbit Around Proxima Centauri
Proxima Centauri b

At a distance of 1.295 parsecs, the red-dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890, or simply Proxima) is the Sun’s closest stellar neighbor and one of the best studied low-mass stars.

It has an effective temperature of only ∼ 3050 K, a luminosity of ∼0.1 per cent solar, a measured radius of 0.14 R⊙ and a mass of about 12 per cent the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is ∼ 83 days, and its quiescent activity levels and X-ray luminosity are comparable to the Sun’s. New observations reveal the presence of a small planet orbiting Proxima with a minimum mass of 1.3~Earth masses and an orbital period of ∼11.2 days. Its orbital semi-major axis is ∼0.05 AU, with an equilibrium temperature in the range where water could be liquid on its surface.

Comments: Version accepted for publication by Nature (unedited, July 7th, 2016), figures inserted in text for easier read. Article body : 10 pages, 3 figures, 1 table. Methods section : 23 pages, 9 figures, 1 table. IMPORTANT NOTE : Acknowledgment to IAA/CSIC researchers Javier Pascual Granado and Rafael Garrido added for useful discussions and feedback on the mathematical properties of time-series

Guillem Anglada-Escudé, Pedro J. Amado, John Barnes, Zaira M. Berdiñas, R. Paul Butler, Gavin A. L. Coleman, Ignacio de la Cueva, Stefan Dreizler, Michael Endl, Benjamin Giesers, Sandra V. Jeffers, James S. Jenkins, Hugh R. A. Jones, Marcin Kiraga, Martin Kürster, María J. López-González, Christopher J. Marvin, Nicolás Morales, Julien Morin, Richard P. Nelson, José L. Ortiz, Aviv Ofir, Sijme-Jan Paardekooper, Ansgar Reiners, Eloy Rodríguez, Cristina Rodríguez-López, Luis F. Sarmiento, John P. Strachan, Yiannis Tsapras, Mikko Tuomi, Mathias Zechmeister
(Submitted on 12 Sep 2016)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference: Nature 536 (2016) 437-440
DOI: 10.1038/nature19106
Cite as: arXiv:1609.03449 [astro-ph.EP] (or arXiv:1609.03449v1 [astro-ph.EP] for this version)
Submission history
From: Guillem Anglada-Escude [view email]
[v1] Mon, 12 Sep 2016 15:39:25 GMT (1182kb)

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