Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

The CORALIE survey for southern extra-solar planets XV. Discovery of two eccentric planets orbiting HD 4113 and HD 156846

O. Tamuz, D. Ségransan, S. Udry, M. Mayor, P. Eggenberger, D. Naef, F. Pepe, D. Queloz, N. C. Santos, B.-O. Demory, P. Figuera, M. Marmier, G. Montagnier

We report the detection of two very eccentric planets orbiting HD 4113 and HD 156846 with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope at La Silla. The first planet, HD 4113 b, has minimum mass of msin i = 1:6  0:2 MJup, a period of P = 526:59  0:21 days and an eccentricity of e = 0:903  0:02. It orbits a metal rich G5V star at a = 1:28AU which displays an additional radial velocity drift of 28 ms^1/yr observed during 8 years. The combination of the radial-velocity data and the non-detection of any main sequence stellar companion in our high contrast images taken at the VLT with NACO/SDI, characterizes the companion as a probable brown dwarf or as a faint white dwarf. The second planet, HD 156846 b, has minimum mass of msin i = 10:45  0:05 MJup, a period of P = 359:51  0:09 days, an eccentricity of e = 0:847  0:002 and is located at a = 1:0 AU from its parent star. HD156846 is a metal rich G0 dwarf and is also the primary of a wide binary system (a > 250AU, P > 4000 years). Its stellar companion, IDS 17147-1914 B , is a M4 dwarf. The very high eccentricities of both planets can be explained by Kozai oscillations induced by the presence of a third object.

Astronomy and Astrophysics
Volume 480, Page L33
March 2008

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website