Against my better judgement I peeked in at 4chan Tuesday, whose /sci/ sometimes has a "spaceflight" haven from the usual malarkey. After some banter someone asked about exomoons. Neil Comins' second book had commented about an alien starsystem, with a Jovian in its habitable-zone. So let's check in on Comins: could there be life on that planet's moons?
If we are talking exomoons we need space for the Hill Sphere / L1. To give time for oxygen-emitting life to evolve in lunar oceans (I'll GET to oceans, don't YOU worry...), stellar mass needs G... maybe low F, so 1.2 sols. The HZ then runs, say, 2 of our AU. The Jovian is Sudarsky II.
We do I think sometimes get Jovians with major planets down to 1/4 that semimajor, or above to twice that. Exoplanet.eu offers a few of these with the warning that it doesn't get updated as well as we'd like. For Jovians around G and F as are close (≤30 parsecs) the Gaia DR3 has constrained inclination; here's a take. Our own Jovian carves out space against massive inner planets. So I'll play G-d and rule similarly.
Another worry: Jupiter spawns Galilean-size moons. To get Venus-size moons - plural - we need a double-Jovian. Or triple-.
This watergiant will ionise its inner moons such that atmosphere go bye-bye. Even for us here around Sol, the Jovians are a tough call. Jupiter's radiation starts getting ugly around Ganymede although Ganymede might be able to resist it once we've landed. So - watergiant needs a superCallisto(expialidocious).
Also: watergiant has drifted in from the icier parts of the system.
SuperCallisto expy even allowing a superGanymedean iron core will be a water moon. It has no dry land. Its fauna is fish and sharks. If that; as a F system I'm unsure its evolution will last long enough before its redgiant.
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