orbital_elements_to_xyz#

agabpylib.numerical.astronomy.celestialmechanics.orbital_elements_to_xyz(a, e, incl, lon_nodes, argperi, tau, t)#

For the given Keplerian orbital elements and the epoch t, calculate the position in (x,y,z) in the BCRS.

The inputs can consist of all scalars or a mix of scalars an 1D arrays.

Note

For now orbits with e<1 are assumed. The orbit is treated as that of a test-particle and thus the period is given in multiples of 2*PI/(GM_sun)*(au)^1.5.

Parameters:

  • a (float scalar or 1D-array) – Semi-major axis in au

  • e (float scalar or 1D-array) – Eccentricity

  • incl (float scalar or 1D-array) – inclination in degrees (0-180)

  • lon_nodes (float scalar or 1D-array) – Longitude of the line of nodes in degrees (0-360)

  • argperi (float scalar or 1D-array) – Argument of perihelion in degrees (0-360)

  • tau (float scalar or 1D-array) – Epoch of perihelium passage in yr

  • t (float scalar or 1D-array) – Epoch at which to calculate (x,y,z) in yr

Returns:

x, y, z – Array of values (x,y,z) of shape (N,3)

Return type:

float array of shape (N,3)