Extrasolar Planets

Giant Planets in the Habitable Zone

By Keith Cowing
Press Release
April 27, 2016
Filed under
Giant Planets in the Habitable Zone

We report the discovery of three new substellar companions to solar-type stars, HD191806, HD214823, and HD221585, based on radial velocity measurements obtained at the Haute-Provence Observatory.

Data from the SOPHIE spectrograph are combined with observations acquired with its predecessor, ELODIE, to detect and characterise the orbital parameters of three new gaseous giant and brown dwarf candidates. Additionally, we combine SOPHIE data with velocities obtained at the Lick Observatory to improve the parameters of an already known giant planet companion, HD16175 b. Thanks to the use of different instruments, the data sets of all four targets span more than ten years. Zero-point offsets between instruments are dealt with using Bayesian priors to incorporate the information we possess on the SOPHIE/ELODIE offset based on previous studies.

The reported companions have orbital periods between three and five years and minimum masses between 1.6 Mjup and 19 Mjup. Additionally, we find that the star HD191806 is experiencing a secular acceleration of over 11 \ms\ per year, potentially due to an additional stellar or substellar companion. A search for the astrometric signature of these companions was carried out using Hipparcos data. No orbit was detected, but a significant upper limit to the companion mass can be set for HD221585, whose companion must be substellar.
With the exception of HD191806 b, the companions are located within the habitable zone of their host star. Therefore, satellites orbiting these objects could be a propitious place for life to develop.

SOPHIE search for northern extrasolar planets: Three new companions and an orbit update: Giant planets in the habitable zone

R.F. Díaz (1), J. Rey (1), O. Demangeon (2), G. Hébrard (3,4), I. Boisse (2), L. Arnold (4), N. Astudillo-Defru (1), J.-L. Beuzit (5,6), X. Bonfils (5,6), S. Borgniet (5,6), F. Bouchy (1,2), V. Bourrier (1), B. Courcol (2), M. Deleuil (2), X. Delfosse (5,6), D. Ehrenreich (1), T. Forveille (5,6), A.-M. Lagrange (5,6), M. Mayor (1), C. Moutou (2,7), F. Pepe (1), D. Queloz (1,8), A. Santerne (9), N. C. Santos (9,10), J. Sahlmann (11), D. Ségransan (1), S. Udry (1), P. A. Wilson (3) ((1) Observatoire Astronomique de l’Université de Genève, Versoix, Switzerland, (2) Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) Marseille, France, (3) Institut d’Astrophysique de Paris, CNRS, Université Pierre & Marie Curie, Paris, France, (4) Observatoire de Haute Provence, CNRS, Aix Marseille Université, Institut Pythéas, Saint-Michel-l’Observatoire, France, (5) Univ. Grenoble Alpes, IPAG, Grenoble, France, (6) CNRS, IPAG, Grenoble, France, (7) Canada-France-Hawaii Telescope Corporation, Kamuela, HI, USA, (8) Cavendish Laboratory, Cambridge, UK, (9) Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Porto, Portugal, (10) Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal, (11) European Space Agency, European Space Astronomy Centre, Madrid, Spain)
(Submitted on 26 Apr 2016)

Comments: 12 pages + tables, 7 figures. Accepted for publication in Astronomy & Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1604.07610 [astro-ph.EP] (or arXiv:1604.07610v1 [astro-ph.EP] for this version)
Submission history
From: Rodrigo Díaz Mr.
[v1] Tue, 26 Apr 2016 10:34:58 GMT (268kb)

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