Hello, thank you for reading my post. For a story I am working on I am wondering about the plausibility of some star and planet configurations. I have done some web research on my own and learned a lot, but for some things I think my vocabulary and knowledge is too limited to search for exactly what I want. What I would like to have is a large gas planet (or a brown dwarf) as the lone planet circling a star. Orbiting this planet would be an exomoon, perhaps the size of Titan (a larger, spherical moon). Is it possible for a stable orbit to exist between the planet and moon where the moon is either Orbiting slowly enough so that it is locked between the star and planet, causing a solar eclipse on part of the planet's surface permenantly, or Behind the planet in a line with the star, causing the moon to be permenantly hidden from the star (permenantly in a lunar eclipse)? Is this the same as an object being in the gas planet's L1-L2 points? I have read that these points are not very stable, especially for large objects, for earth anyway, so I wonder how large a moon could exist in the L1-L2 points of a very large planet/brown dwarf. Ideally, for the story, it would be on the range of 3+ billion years.