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(see Fig. 2) by the excitation of the eccentricity; qualitatively, our results
are in accord with those of Paper II.
While the inner edge of HZ marks out a narrow unstable area, it is very
possible to discover Earth-like planets in this wider area, 0.4 AU
<a<
1
.
0 AU, in future surveys, which are to be the best candidate of habitable
places for biological evolution of intelligent beings.
2.1.3. 1
.
0
AU
≤
a<
1
.
3
AU
There were 630 simulations in this region for 10 Myr and we found that
88% survived the integration, confirming the results given in Paper II that
most of the test particles with
a<
1
.
3 AU can eventually remain in the
system. Here, for the 3:1 resonance at
1
.
0 AU, Fig. 3 shows that there are
stable orbits in the zones about 1 AU with
e
∼
0
.
1, which agrees with the
work by Rivera and Haghighipour
19
who showed that a test particle can
last 100 Myr at 1 AU in 47 UMa; while for 0
.
1
<e
≤
0
.
2, the orbits tend
to be in unstable state owing to the excitation of the eccentricities. The
simulations may imply that the Earth-mass planets near 3:1 resonance are
possibly on the edge of stability. However, the previous studies
7
,
10
on this
system showed that the 3:1 resonance is a gap with no survivors. Let us
mention that such differences may arise from the adopted initial planetary
configurations, and here we adopt the reliable best-fit orbital solutions given
≤
Fig. 3. The surviving time for Earth-like planets for the integration of 10 Myr, the
vertical axis for the initial
e
. Case for 1.0 AU
≤ a<
1
.
3 AU, see the gap for the 5:2 MMR
at
∼
1
.
13 AU.
