If you want to make them more realistic, you need to make larger than huge sized planets.
Here's from yesterday's news:
quote:
"The outer companion (of this star) is so massive, between 17 and 40 times the mass of Jupiter, that it seems too large for a conventional planet," Marcy said.
"We frankly don't know what name to give it. Is it a planet or brown dwarf (a dim failed star) or something that formed in the protoplanetary disk, but gobbled an unusual quantity of gas in that disk?" Marcy said. "We simply don't know."
So far only one system (other than ours) has been confirmed to have more than a single planet:
quote:
The other star with two planets circling it is Gliese 876 in the constellation Aquarius, a mere 15 light years from Earth.
Gliese's satellites are more seemly in size, with one planet at least half the mass of Jupiter and the other with nearly twice Jupiter's mass.
What makes them remarkable is their resonant orbits. The smaller planet orbits the star twice for every one 60-day orbit of the bigger planet, the astronomers said. This synchrony may have led astronomers to believe there was just one planet around the star, according to astronomer Jack Lissauer of the NASA Ames Research Center.
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