I’m working on a fantasy novel and trying to keep the underlying science internally consistent so obviously i have some questions since im not a science person.
How possible is it for a planet in an S-type orbit around one star in a binary system, with the entire system orbiting a black hole to have life?
Could the secondary star have a long enough orbital period (thousands of years) that environmental conditions on the planet could change slowly enough for civilizations to rise and fall between different phases?
If a system like this orbits a black hole at a safe distance, could its effects vary over time, or would they be effectively constant?
If the black hole has an accretion disk and the system far enough that it remains habitable, would that disk realistically be visible from the planet?
Some more context about the setting, The planet orbits a relatively cool primary star. A hotter secondary star orbits at a much grater distance and it influences the planet’s climate depending on its distance, making the environment periodically more or less habitable. During the story, the second star is at a distance where the weather is getting noticeably warmer but there is no doomsday panic yet.
The black hole isn’t really an immediate “threat”. The main driver of the conditions on the planet is the suns. I want to focus more on how living in orbit of a black hole could effect life on the planet.
I’m also fully aware that a world like this would be very unlikely to produce complex life and repeated civilizations in real life. I’m willing to assume that life somehow found a way, what I’m trying to figure out is whether the astronomy and planetary effects can be made plausible enough around that assumption.
Also keep in mind this is a fantasy story, not sci-fi. The science won’t be explicitly explained in story nor will the reality of what’s going on with the stars or the black hole ever be understood by the characters. My goal is just for the world to be built in a way that the “fantasy” could be interpreted through science and logic. So all this is really just subtext in a story where people probably don’t even know there are two suns in the sky.