A&A 474, 1023-1029 (2007)
Survey of the stability region of hypothetical habitable Trojan planetsR. Schwarz1, 2, R. Dvorak1, Á. Süli2, and B. Érdi2
1 Institute for Astronomy, University of Vienna, Türkenschanzstr. 17, 1180 Wien, Austria
2 Department of Astronomy, Eötvös University, Pázmány Péter sétány 1/A, Budapest 1117, Hungary
(Received 1 June 2007 / Accepted 13 August 2007)
Aims.In this work we study the dynamical possibility in extrasolar planetary systems that a terrestrial planet can exist in 1:1 mean motion resonance with a Jovian-like planet. We compiled a catalogue of hypothetical habitable Trojan planets, to be able to make a stability forecast for further extrasolar planetary systems discovered in the future. When speaking of habitability we also took the influence of the spectral type of the central star into account.
Methods.We integrated some 106 orbits of fictitious Trojans around the Lagrangian points for up to 107 orbital periods of the primary bodies and checked the stability of the orbital elements and their chaoticity with the aid of the Lyapunov characteristic indicator and maximum eccentricity. The computations were carried out using the dynamical model of the elliptic, restricted three-body problem that consists of a central star, a gas giant moving in the habitable zone, and a hypothetical (massless) terrestrial planet.
Results.Our investigations have shown that 7 exoplanetary systems can harbour habitable Trojan planets with stable orbits (HD 93083, HD 17051, HD 28185, HD 27442, HD 188015, HD 99109, and HD 221287, which is a recently discovered system). The comparison of the investigated systems with our catalogue showed matching results, so that we can use the catalogue in practice.
Key words: celestial mechanics -- stars: planetary systems -- astrobiology
© ESO 2007