Monday, July 11, 2005

A pair of planets around HD 202206 or a circumbinary planet?

A pair of planets around HD 202206 or a circumbinary planet?
Authors: A.C.M. Correia, S. Udry, M. Mayor, J. Laskar, D. Naef, F. Pepe, D. Queloz, N.C. Santos
Comments: 9 pages, 14 figures, accepted in A&A, 12-May-2005

Long-term precise Doppler measurements with the CORALIE spectrograph reveal the presence of a second planet orbiting the solar-type star HD202206. The radial-velocity combined fit yields companion masses of m_2\sini = 17.4 M_Jup and 2.44 M_Jup, semi-major axes of a = 0.83 AU and 2.55 AU, and eccentricities of e = 0.43 and 0.27, respectively. A dynamical analysis of the system further shows a 5/1 mean motion resonance between the two planets. This system is of particular interest since the inner planet is within the brown-dwarf limits while the outer one is much less massive. Therefore, either the inner planet formed simultaneously in the protoplanetary disk as a superplanet, or the outer Jupiter-like planet formed in a circumbinary disk. We believe this singular planetary system will provide important constraints on planetary formation and migration scenarios





The link to the PDF of the paper is here.

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