lib_elp2000_moon

28. Dez. 2025

Library "lib_elp2000_moon"

get_geo_ecl_lon(T)
  Parameters:
    T (float)

get_geo_ecl_lat(T)
  Parameters:
    T (float)

get_obliquity(T)
  Parameters:
    T (float)

get_declination(T)
  Parameters:
    T (float)

get_true_node_lon(T)
  Parameters:
    T (float)

get_true_south_node_lon(T)
  Parameters:
    T (float)

get_node_declination(T)
  Parameters:
    T (float)

get_south_node_declination(T)
  Parameters:
    T (float)

16. Jan.

Versionshinweise

v2
Exported the mean node functions that were previously internal. Node declination now uses the mean node instead of the true node, which is more consistent than the low-precision true-node perturbations. Functions renamed to "North/South" for astrological clarity.

Added:
get_mean_north_node_lon(T)
  Returns mean longitude of the Moon's North Node (ascending node).
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Longitude in degrees, range [0, 360).
note Mean node is a simple averaged calculation, reducing computational error. Used for declination calculations.

get_mean_south_node_lon(T)
  Returns mean longitude of the Moon's South Node (descending node).
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Longitude in degrees, range [0, 360). Equals North Node + 180°.

get_true_north_node_lon(T)
  Returns true longitude of the Moon's North Node with perturbation corrections.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Longitude in degrees, range [0, 360).
note True node includes periodic perturbations but formula is low precision. Consider using mean node for consistency.

get_north_node_declination(T)
  Returns declination of the Moon's North Node.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Declination in degrees, range [-23.4, +23.4] (bounded by obliquity).
note Uses mean node for calculation (more consistent than true node).

Updated:
get_geo_ecl_lon(T)
  Returns geocentric ecliptic longitude of the Moon.
  Parameters:
    T (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries).
  Returns: (float) Longitude in degrees, range [0, 360).

get_geo_ecl_lat(T)
  Returns geocentric ecliptic latitude of the Moon.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Latitude in degrees.

get_obliquity(T)
  Returns mean obliquity of the ecliptic.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Obliquity in degrees.

get_declination(T)
  Returns geocentric equatorial declination of the Moon.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Declination in degrees, range [-90, +90] where positive is north.

get_true_south_node_lon(T)
  Returns true longitude of the Moon's South Node with perturbation corrections.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Longitude in degrees, range [0, 360). Equals True North Node + 180°.

get_south_node_declination(T)
  Returns declination of the Moon's South Node.
  Parameters:
    T (float): (float) Julian centuries from J2000.0.
  Returns: (float) Declination in degrees. Inverse of North Node declination.

Removed:
get_true_node_lon(T)

get_node_declination(T)