World building and Planetary System Generation

Almost halfway through June already. I was looking at another diamond/square tutorial, AKA random midpoint displacement, cloud or plasma fractal, which I could implement to triangle subdivision as I want or need it. I would make a tetra or octa and set the vertices to some height, then start subdividing the midpoints with PR# seeds based on position. The four inputs would be the two endpoints and the far corners of the adjacent triangles and I probably should weight them based on distance but doubling up on the endpoints and dividing by six should do. In other news I had also asked the SFIA feeb page for help today with an updated star system generator based on the universe as we find it vs. building solar system clones, but the responses I got indicated that they didn't understand my question. I guess I will have to figure this out on my own (“Fine! I’ll do it myself…”).

So, we make a star, randomly generate a mass, get one from user input or perhaps a PR# positional seed by clicking in the canvas rectangle. The star has a metallicity and age which affects luminosity, but we will ignore this for now and derive luminosity as mass^4.5, the four and a half power, so small stars are dim and cooler and large stars are very bright and hotter. They also live fast and die young, whereas smaller stars last longer, perhaps much longer because they also tend to churn through all their volume and burn all of the hydrogen.

From mass and luminosity we can determine the distribution and composition of mass in a planetary accretion disk. The ‘frost line’ is the point at which most of the lighter hydrogen, helium and water are driven off, out into the outer solar system, so we get rocky inner planets and outer gas giants like Jupiter or Saturn or ice giants like Uranus (Elsa! Herschel!)  and Neptune. We can model planetary accretion once we know what we are accreting. The formation snowline is farther out and I have one source which suggests 5 AU for the solar system, 5*luminosity^½ for a different star system, or maybe 5*mass^2 since this is all before the star lights off, while accretion is happening in a cooler environment.

Continuing on, my accretion disk model has a thinner but higher density inner component and a thicker and more massive but lower density outer component. I want to chunk up the disk into rings. The mass inventory is some fairly large value, greater than about 500 earth masses for the solar system, because that is the sum of all the major planets and we believe that the gas giants, principally Jupiter, have ejected mass from the solar system or dropped it into the sun. What I need to do here is to start accreting protoplanets, and have those protoplanets move around, collide, get ejected or dropped into the sun… I can do random subdivision of the disk, making a list of zones, masses and accreting a seed from some fraction of the mass of that ring within the disk.