lib_meeus_pluto

Library "lib_meeus_pluto"
Heliocentric and geocentric position calculations for Pluto using
Meeus truncated analytical series. Valid ±1 century from J2000.

Author BlueprintResearch (Javonnii)
license MIT License - Free to use with attribution

theory Meeus truncated series (not full planetary theory)
ACCURACY Arcminute precision within ±1 century of J2000
@time_scale Julian centuries from J2000.0 (use core.get_julian_centuries)

reference Meeus, Jean. "Astronomical Algorithms" (2nd Ed., 1998), Chapter 37

showcase Includes commented showcase code with 250-bar future projection.
Uncomment to display Pluto data with polyline projections.

@open_source This library is part of an open-source alternative to
proprietary astronomical libraries. Study, modify, and
share freely. We believe knowledge of the cosmos belongs
to everyone.

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© 2025 BlueprintResearch / Javonnii
Licensed under MIT License
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version=6
import BlueprintResearch/lib_vsop_core/1 as core

get_helio_lon(t)
  Computes Pluto's heliocentric ecliptic longitude using Meeus truncated analytical series.
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Heliocentric ecliptic longitude in degrees, normalized to range [0, 360). Accurate within ±1 century from J2000.

get_helio_lat(t)
  Computes Pluto's heliocentric ecliptic latitude using Meeus truncated analytical series.
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Heliocentric ecliptic latitude in degrees, range approximately [-17, +17]. Accurate within ±1 century from J2000.

get_helio_radius(t)
  Computes Pluto's heliocentric radius (distance from Sun) using Meeus truncated analytical series.
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Heliocentric radius in astronomical units (AU). Typical range is 29.6-49.3 AU. Accurate within ±1 century from J2000.

get_geo_lon(t)
  Computes Pluto's geocentric ecliptic longitude (as seen from Earth).
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Geocentric ecliptic longitude in degrees, normalized to range [0, 360).

get_geo_ecl_lat(t)
  Computes Pluto's geocentric ecliptic latitude (as seen from Earth).
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Geocentric ecliptic latitude in degrees, range approximately [-17, +17].

get_geo_decl(t)
  Computes Pluto's geocentric equatorial declination (as seen from Earth).
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Geocentric equatorial declination in degrees, range [-90, +90] where positive is north.

get_geo_speed(t)
  Computes Pluto's geocentric longitude speed (rate of change over time).
  Parameters:
    t (float): (float) Julian centuries from J2000.0 (use core.get_julian_centuries(time)).
  Returns: (float) Geocentric longitude speed in degrees per day. Negative values indicate retrograde motion (apparent backward movement).