Characteristics of the closest known G-type exoplanet host 82 Eri

Authors


E-mail: jan.bernkopf@hs-augsburg.de

ABSTRACT

We present a consistent model atmosphere analysis and evolutionary tracks for the very nearby G-type star 82 Eri that was most recently announced by Pepe et al. to harbour two or three super-Earth companions with orbital periods of 18, 40 and 90 d. As a bright and high-velocity object, 82 Eri was already realized by Jan Hendrik Oort in his 1926 treatise to be of ‘probably different origin’ and we confirm its being a member of the ancient thick-disc population on account of its outstanding iron-to-magnesium deficiency. Thus, in our immediate neighbourhood – only 6 pc away – there exists a system of extremely old and probably rocky super-Earths that were already formed when the Milky Way was at its infancy, 12 or even 13 billion years in the past.

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