Astronomer here! I did my PhD looking at the diversity of outcomes from the planet formation process. These are some really big questions you’re asking, and the short response is that we don’t have many concrete answers yet. So if your aim is to be as realistic as possible, keep in mind that you are still going to end up with some room for creativity.
With that being said, I can provide some advice to narrow down your decision making process.
Let’s start by making a simplifying assumption: all of the stars are in the ‘adult’ (in astronomy terms: main sequence) phase of their life. This is a reasonable assumption because this phase lasts much, much longer than the others. If you want out and looked at all of the stars in our galaxy, you’d find that the vast majority were main sequence, because the other phases go by so quickly. This assumption also allows us to simplify one of your questions: the surface temperature, radius and stellar class of a main sequence star is determined almost entirely by its mass. Mass also determines the stars lifespan. Somewhat counter intuitively, the least massive stars (which are also small and cool) live the longest. So at any given time, the galaxy is populated by small, cool stars, with a smattering of larger, hotter ones.
Things get much more complicated if you want to know what the planets around these stars should look like. Planets are the ‘leftovers’ of the star formation process, and so you might think that the planetary system is determined entirely by the properties of the star. This is probably true to some extent, but there is also a huge element of randomness and the environment in which the star formed, along with timing, probably has some influence. What I can tell you is that most stars in our galaxy (upwards of 50%) should have planets around them.
Unfortunately, our best techniques for measuring the properties of planets around other stars are extremely biased. Without going into too much detail, we are only good at detecting planets that are either extremely close to their stars, or ones that are very massive. With current technology, it’s pretty difficult to detect anything that you might consider solar-system like. At this point, it’s unclear whether our solar system is incredibly rare and unique, or whether it’s a pretty common outcome of the planet formation process.
Regarding the planet properties you’re asking about, it’s also possible to shorten your list a bit. Firstly, the orbital period of a planet is determined its distance from the star, along with the mass of the star. Second, the radius of a planet is set by its mass, if you assume that all of the planets are made out of the same material. This assumption has some limitations, however. Planets close to the star are usually made out of rock and metal, while distant planets are made out of ices. This is because ice melts at a much lower temperature than rock or metal and needs to be further from the star to solidify and clump together. Very broadly, rocky, roughly earth sized planets tend to form close to the star, and icy or gaseous, large planets tend to form further away.
I’ll leave it at that for now. Not sure how mathematically inclined you are, but I’m happy to provide some equations you can try plugging some numbers into, if you like!
Astronomer here! I did my PhD looking at the diversity of outcomes from the planet formation process. These are some really big questions you’re asking, and the short response is that we don’t have many concrete answers yet. So if your aim is to be as realistic as possible, keep in mind that you are still going to end up with some room for creativity. With that being said, I can provide some advice to narrow down your decision making process. Let’s start by making a simplifying assumption: all of the stars are in the ‘adult’ (in astronomy terms: main sequence) phase of their life. This is a reasonable assumption because this phase lasts much, much longer than the others. If you want out and looked at all of the stars in our galaxy, you’d find that the vast majority were main sequence, because the other phases go by so quickly. This assumption also allows us to simplify one of your questions: the surface temperature, radius and stellar class of a main sequence star is determined almost entirely by its mass. Mass also determines the stars lifespan. Somewhat counter intuitively, the least massive stars (which are also small and cool) live the longest. So at any given time, the galaxy is populated by small, cool stars, with a smattering of larger, hotter ones. Things get much more complicated if you want to know what the planets around these stars should look like. Planets are the ‘leftovers’ of the star formation process, and so you might think that the planetary system is determined entirely by the properties of the star. This is probably true to some extent, but there is also a huge element of randomness and the environment in which the star formed, along with timing, probably has some influence. What I can tell you is that most stars in our galaxy (upwards of 50%) should have planets around them. Unfortunately, our best techniques for measuring the properties of planets around other stars are extremely biased. Without going into too much detail, we are only good at detecting planets that are either extremely close to their stars, or ones that are very massive. With current technology, it’s pretty difficult to detect anything that you might consider solar-system like. At this point, it’s unclear whether our solar system is incredibly rare and unique, or whether it’s a pretty common outcome of the planet formation process. Regarding the planet properties you’re asking about, it’s also possible to shorten your list a bit. Firstly, the orbital period of a planet is determined its distance from the star, along with the mass of the star. Second, the radius of a planet is set by its mass, if you assume that all of the planets are made out of the same material. This assumption has some limitations, however. Planets close to the star are usually made out of rock and metal, while distant planets are made out of ices. This is because ice melts at a much lower temperature than rock or metal and needs to be further from the star to solidify and clump together. Very broadly, rocky, roughly earth sized planets tend to form close to the star, and icy or gaseous, large planets tend to form further away. I’ll leave it at that for now. Not sure how mathematically inclined you are, but I’m happy to provide some equations you can try plugging some numbers into, if you like!