The SOPHIE search for northern extrasolar planets.
VII. A warm Neptune orbiting HD 164595

B. Courcol, F. Bouchy, F. Pepe, A. Santerne, X. Delfosse, L. Arnold, N. Astudillo, I. Boisse, X. Bonfils, S. Borgniet, V. Bourrier, N. Cabrera Salazar, M. Deleuil, O. Demangeon, R. F. Díaz, D. Ehrenreich, T. Forveille, G. Hébrard, A.-M. Lagrange, G. Montagnier, C. Moutou, J. Rey Cerda, N. C. Santos, D. Ségransan, S. Udry, P. A. Wilson

Abstract
High-precision radial velocity surveys explore the population of low-mass exoplanets orbiting bright stars. This allows accurately deriving their orbital parameters such as their occurrence rate and the statistical distribution of their properties. Based on this, models of planetary formation and evolution can be constrained. The SOPHIE spectrograph has been continuously improved in past years, and thanks to an appropriate correction of systematic instrumental drift, it is now reaching 2 m s-1precision in radial velocity measurements on all timescales. As part of a dedicated radial velocity survey devoted to search for low-mass planets around a sample of 190 bright solar-type stars in the northern hemisphere, we report the detection of a warm Neptune with a minimum mass of 16.1 ± 2.7M orbiting the solar analog HD 164595 in 40 ± 0.24 days. We also revised the parameters of the multiplanetary system around HD 190360. We discuss this new detection in the context of the upcoming space mission CHEOPS, which is devoted to a transit search of bright stars harboring known exoplanets.

Keywords
planetary systems, techniques: radial velocities, stars: individual: HD 164595, stars: individual: HD 190360, stars: individual: HD 185144

Astronomy and Astrophysics
Volume 581, Page A38
September 2015

DOI: 10.1051/0004-6361/201526329
ADS Bibliographic code: 2015A%26A...581A..38C