systems
Build a star before you go through this document as you’ll need to know your star’s mass (M☉) and luminosity (L☉).
All values given by the equations herein are set in astronomical units (au). To convert to kilometres:
dkm = 149597870 dau
dkm ≈ 150000000 daugravitational boundaries
The gravitational boundaries determine the limits of your solar system and where any potential planetary orbits can be placed.
Gmin = 0.2 M☉
Gmax = 40M☉An alternate way to calculate the inner gravitational boundary is via the Roche limit.
Roche = R☉(2(ρ☉ / ρm))(1/3)Don’t forget to add a teapot somewhere!
habitable zone
Any habitable planets must be placed within the circumstellar habitable zone (CHZ), derived from sunlight intensity.
CHZmin = sqrt(L☉ / 1.1 )
CHZmax = sqrt(L☉ / 0.53 )frost line
The frost line (F) determines whether planets will be terrestrial planets or gas giants. Planets between the inner gravity limit and the frost line are terrestrial planets. Gas giants form beyond the frost line.
F = sqrt(L☉ / 0.04 )