A direction in the system's own reference frame, as a longitude in the
reference plane (degrees from +x, counter-clockwise seen from +z) and a
latitude out of it (degrees, +90 = straight up +z). For the bundled
Solar System that frame is the J2000 ecliptic, so this is ecliptic
longitude/latitude; see poleFromEquatorialJ2000 (orientation.ts) for
converting the IAU's published right ascension/declination into it.
A direction in the system's own reference frame, as a longitude in the reference plane (degrees from +x, counter-clockwise seen from +z) and a latitude out of it (degrees, +90 = straight up +z). For the bundled Solar System that frame is the J2000 ecliptic, so this is ecliptic longitude/latitude; see poleFromEquatorialJ2000 (orientation.ts) for converting the IAU's published right ascension/declination into it.