Four features, 10 new SQL functions (174 → 184 objects), 29 test suites:
Saturn ring tilt: saturn_ring_tilt() exposes sub-observer latitude B'.
planet_magnitude() for Saturn now includes Mallama & Hilton Eq. 10
ring correction (-2.60|sin B'| + 1.25 sin²B'), removing the ~1.5 mag
globe-only caveat. IAU 2000 pole direction, ecliptic J2000 projection.
Conical shadow model: Replaces cylindrical shadow with umbra/penumbra
cones using Sun's finite angular size. Four new functions:
satellite_in_penumbra(), satellite_shadow_state(),
satellite_next_penumbra_entry/exit(). Existing eclipse functions are
backward compatible via narrower (more accurate) umbra boundary.
Rise/set event windows: Three SRFs returning TABLE(event_time, event_type)
for all rise/set events within a time window — planet_rise_set_events(),
sun_rise_set_events(), moon_rise_set_events(). Follows predict_passes()
SRF pattern. Optional refracted parameter, 366-day window limit.
Angular separation rate: Vincenty formula extracted to reusable helper.
eq_angular_rate() for generic finite-difference rate, planet_angular_rate()
for solar system body convenience (1-minute dt, handles Sun/planets/Moon).
