Geoscience Reference
In-Depth Information
Fig. 1. The contour of status of the final eccentricities for Earth-like planets, the vertical
axis for the initial
e
. Case for 0.05 AU
≤ a<
0
.
4 AU for 1 Myr. Notice
ν
1
secular resonance
at
∼
0
.
30 AU pumps up the eccentricities.
Fig. 1 shows that the eccentricities for bodies at
∼
0
.
30 AU are excited to
0
.
40, where the secular resonance
ν
1
(41
.
11/years) of the inner compan-
ion (similar to
ν
5
for Jupiter) is responsible for the excitation of eccentricity.
The debris disk at
∼
0
.
30 AU is also shown by Malhotra,
18
who presented
similar results of the eccentricity excitation of massless bodies by nonlinear
analytic theory for secular resonance. Nevertheless, one can easily see that
this region is not a good location for habitability, due to extra high tem-
perature. G. W. Marcy (2004, private communication) pointed out that
the improvement of precision of the ground-based observations will lead
to the discovery of additional low-mass planets (
∼
10 M
⊕
)inotherknown
planetary systems. In addition, it is hopeful to detect such planets with
a
∼
≥
0
.
05 AU in future space missions (e.g., COROT, KEPLER, TPF).
2.1.2. 0
.
4
AU
≤
a<
1
.
0
AU
We carried out 1,260 integrations in this region for 5 Myr and we found
that none of the orbits escaped during this time span and 94% of them
were in the resulting
e<
0
.
25, see the final status shown in Fig. 2. We find
that the eccentricities of the orbits with 0.70 AU
<a<
0.78 AU can be
