EDP Sciences
Free Access
Volume 462, Number 3, February II 2007
Page(s) 1165 - 1170
Section Planets and planetary systems
DOI https://doi.org/10.1051/0004-6361:20066284

A&A 462, 1165-1170 (2007)
DOI: 10.1051/0004-6361:20066284

Trojan planets in HD 108874?

R. Schwarz1, R. Dvorak2, E. Pilat Lohinger2, Á. Süli1, and B. Érdi1

1  Eötvös Loránd University, Departement of Astronomy, Pázmány Péter sétány 1/A, Budapest 1518, Hungary
2  Institute for Astronomy, University of Vienna, Türkenschanzstr. 17, 1180 Wien, Austria
    e-mail: dvorak@astro.univie.ac.at

(Received 22 August 2006 / Accepted 16 October 2006)

Aims.It turned out recently that, in addition to a large planet with a semimajor axis $a \sim 1$ AU and a low eccentricity ( $e \sim 0.07$), the extrasolar planetary system HD 108874 harbors another massive planet with $2.43~{\rm AU} < a < 2.93 $ AU. The inner planet is orbiting the G5 host star in the habitable zone (=HZ); so that we could established stable regions for Earth-like Trojan planets.
Methods.We integrated some 105 orbits of fictitious Trojans around the Lagrangian points for up to 107 years and checked the stability of the orbital elements and their chaoticity with the aid of the Fast Lyapunov Indicator.
Results.It turns out that this multiplanetary system is the first one where - with the uncertainties in eccentricity and semimajor axes of the outer planet - the existence of Trojan terrestrial planets in stable orbits in the HZ is possible for some combinations of the orbital parameters.

Key words: celestial mechanics -- chaos -- stars: planetary systems

© ESO 2007