Conventions

Units

jaxoplanet does not support units handling. Instead, all inputs to jaxoplanet functions must be converted to the units specified in their respective documentation. Throughout the codebase, the following units are consistently used:

• Lengths are in solar radii (\(R_\odot\)).

• Masses are in solar masses (\(M_\odot\)).

• Times are in days.

• Angles are in radians.

Spherical harmonics

In jaxoplanet, spherical harmonics are real and normalized. They are represented by a 1D vector of coefficient \(y\) ordered by \(l\) and \(m\) such that

\[ y = [Y_{0,0}, Y_{1,-1}, Y_{1,0}, Y_{1,1}, Y_{2,-2}, Y_{2,-1}, Y_{2,0}, Y_{2,1}, Y_{2,2}, ... ] \]

For reference, here’s what the first several spherical harmonic degrees look like:

Coordinates