Rotational flattening, from the Darwin–Radau relation:
f = (5/2)·q / (1 + (25/4)·(1 − (3/2)·C)²), q = ω²R³/GMq is the spin's share of gravity at the equator and C is the moment of
inertia factor, which is what lets the relation know that a giant keeps its
mass in the middle and resists being flung out more than a uniform fluid
would. It is the standard planetary-science relation for a body in
hydrostatic equilibrium, and it earns its place here by hitting the four
bodies whose insides are published: with their own C, Jupiter reads
6.6% against a measured 6.5, Saturn 9.85 against 9.8, Earth 0.333 against
0.335, Neptune 1.77 against 1.71. The uniform-fluid Maclaurin form,
f = (5/4)·q, is the C = 0.4 limit of the same expression, and it gave
Jupiter 11% — so a generated giant in a ten-hour day was drawn twice as
oblate as Saturn, and a puffy one hit the model's ceiling.
Every body in solar/bodies.ts carries its measured polar radius and
never reads this; a generated one has nothing else to derive a figure from,
and a sphere is not the neutral choice, it is the wrong one. Above
HYDROSTATIC_SPIN_LIMIT the spheroid is not the answer either — the
Maclaurin sequence hands over to Jacobi ellipsoids near a flattening of
0.42 — and the spin draws floor the period at that limit, so this is
capped there only for an input nothing generates.
- massnumber
- Undocumented
- radiusnumber
- Undocumented
- rotationPeriodnumber
- Undocumented
- momentFactornumber
- Undocumented