Cometary Elements

py_outfit.orbit_type.cometary.CometaryElements

CometaryElements(
    reference_epoch: float,
    perihelion_distance: float,
    eccentricity: float,
    inclination: float,
    ascending_node_longitude: float,
    periapsis_argument: float,
    true_anomaly: float,
)

Cometary orbital elements (q, e ≥ 1, i, Ω, ω, ν).

Units

• reference_epoch: MJD (TDB)
• perihelion_distance (q): AU
• eccentricity (e): dimensionless; e = 1 parabolic, e > 1 hyperbolic
• inclination (i): radians
• ascending_node_longitude (Ω): radians
• periapsis_argument (ω): radians
• true_anomaly (ν): radians at reference epoch

See also

• to_keplerian — Convert to Keplerian (hyperbolic only).
• to_equinoctial — Convert to Equinoctial (hyperbolic only).

RETURNS	DESCRIPTION
CometaryElements	A new cometary element set.

reference_epoch property

reference_epoch: float

Reference epoch of the element set (MJD, TDB).

perihelion_distance property

perihelion_distance: float

Perihelion distance q (AU).

eccentricity property

eccentricity: float

Eccentricity e (dimensionless). For cometary: e ≥ 1.

inclination property

inclination: float

Inclination i (radians).

ascending_node_longitude property

ascending_node_longitude: float

Longitude of the ascending node Ω (radians).

periapsis_argument property

periapsis_argument: float

Argument of periapsis ω (radians).

true_anomaly property

true_anomaly: float

True anomaly ν at the reference epoch (radians).

to_keplerian

to_keplerian() -> KeplerianElements

Convert cometary → Keplerian elements.

RETURNS	DESCRIPTION
KeplerianElements	if e > 1.

RAISES	DESCRIPTION
* `ValueError` if `e == 1` (parabolic case unsupported by this conversion).

to_equinoctial

to_equinoctial() -> EquinoctialElements

Convert cometary → Equinoctial elements.

RETURNS	DESCRIPTION
EquinoctialElements	if e > 1

RAISES	DESCRIPTION
* `ValueError` if `e == 1` (parabolic case unsupported by this conversion).