EDP Sciences
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Volume 393, Number 3, October III 2002
Page(s) 1015 - 1026
Section Formation and evolution of planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20021138

A&A 393, 1015-1026 (2002)
DOI: 10.1051/0004-6361:20021138

The stability of the orbits of Earth-mass planets in the habitable zone of 47 Ursae Majoris

B. W. Jones and P. N. Sleep

Astronomy Group, The Open University, Milton Keynes, MK7 6AA, UK

(Received 11 April 2002 / Accepted 1 August 2002 )

We have investigated whether Earth-mass planets could survive in the habitable zone (HZ) of the 47 Ursae Majoris system. Mixed-variable symplectic numerical integration has been used to investigate the orbits of putative Earth-mass planets. Whereas the 47 UMa system as previously known, with just one giant planet, could have Earth-mass planets that remain confined to the HZ for a fairly wide range of initial obital parameters, the second (outer) giant now known to be present has reduced the range significantly. There are however confined orbits particularly if either the present eccentricity of the outer giant is close to zero, or the giant masses are close to the minimum values. We have also shown that the eccentricity of the outer giant's orbit is unlikely to exceed about 0.15 at minimum giant mass and 0.13 at 1.5 times this minimum.

Key words: stars: planetary systems -- planets and satellites: general

Offprint request: B. W. Jones, B.W.Jones@open.ac.uk

© ESO 2002