Issue |
A&A
Volume 410, Number 2, November I 2003
|
|
---|---|---|
Page(s) | L13 - L16 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20031404 | |
Published online | 17 November 2003 |
Letter to the Editor
A study of the stable regions in the planetary system HD 74156 – Can it host earthlike planets in habitable zones?
Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
Corresponding author: R. Dvorak, dvorak@astro.univie.ac.at
Received:
2
July
2003
Accepted:
11
September
2003
Using numerical methods we thoroughly investigate dynamical
stability in the region between the two planets found in HD 74156.
The two planets
with
semimajor axes 0.28 AU and 3.82 AU move on quite eccentric orbits
( and 0.354). There is a region between 0.7 and 1.4 AU which may host
additional planets which we checked via
numerical integrations for different dynamical models.
Besides the orbital evolution of several thousands of massless planets
in a three-dimensional restricted 4-body problem
(host star, two planets + massless bodies) we also
have undertaken test computations of the orbital evolution
of fictitious planets with masses of 0.1, 0.3 and 1
in the region between HD 74156b and HD 74156c.
For direct numerical integrations up to 107 years we used the Lie-integrator,
a method with adaptive step-size. We also computed the Fast Lyapunov Indicators
to detect chaotic motion in this region. We emphasize the important rôle
of the inner resonances (with the outer planet) and outer resonances (with
the inner planet) with test bodies located inside the resonances. In these two “resonance” regions
almost no orbits survive. The region between
the 1:5 outer resonance (0.8 AU) and the 5:1 inner resonance (1.3 AU), just in the right
position for habitability, is also not very likely to host planets.
Our results do not strictly “forbid” planets to move in the habitable zone, but their existence
is unlikely.
Key words: stars: individual: HD 74156 / stars: planetary systems / habitable zones
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.