TwoBodyKeplerElements

class twobody.TwoBodyKeplerElements(*, P=None, a=None, m1=None, m2=None, e=0, omega=None, i=None, Omega=None, M0=None, t0=None, units=None)

Bases: BaseKeplerElements

Keplerian orbital elements for a two-body system.

You can either specify period, P and the masses m1, m2, or the separation a and the two masses.

Parameters

Pquantity_like [time]

Orbital period.

aquantity_like [length]

Semi-major axis of the fictitious particle

enumeric (optional)

Orbital eccentricity. Default is circular, e=0.

omegaquantity_like, Angle [angle]

Argument of pericenter.

iquantity_like, Angle [angle]

Inclination of the orbit.

Omegaquantity_like, Angle [angle]

Longitude of the ascending node of the fictitious particle.

M0quantity_like, Angle [angle] (optional)

Mean anomaly at epoch t0. Default is 0º if not specified.

t0quantity-like, numeric, Time (optional)

Reference epoch. Default is J2000 if not specified.

unitsUnitSystem, iterable (optional)

The unit system to represent quantities in. The default unit system is accessible as KeplerElements.default_units.

Attributes Summary

M0
Omega
P
a
e
i
m1
m2
names
omega
primary	Shorthand for .get_body('1').
secondary	Shorthand for .get_body('2').

Methods Summary

get_body(num)

Get the orbital elements for the specified body.

Attributes Documentation

M0

Omega

P

a

e

i

m1

m2

names = ['P', 'a', 'e', 'm1', 'm2', 'omega', 'i', 'Omega', 'M0']

omega

primary

Shorthand for .get_body('1'). Returns the orbital elements for the primary body, which corresponds to m1 (not the more massive of the two).

secondary

Shorthand for .get_body('2'). Returns the orbital elements for the secondary body, which corresponds to m2 (not the less massive of the two).

Methods Documentation

get_body(num)

Get the orbital elements for the specified body.

Parameters

numstr (‘1’ or ‘2’)

Get the orbital elements of the primary '1' or secondary '2'.

Returns

elementstwobody.KeplerElements