Neptune examples¶
Let’s define a small helper function:
def print_me(msg, val):
print("{}: {}".format(msg, val))
We can compute the geometric heliocentric position for a given epoch:
epoch = Epoch(2018, 10, 27.0)
lon, lat, r = Neptune.geometric_heliocentric_position(epoch)
print_me("Geometric Heliocentric Longitude", lon.to_positive())
# Geometric Heliocentric Longitude: 345.3776
print_me("Geometric Heliocentric Latitude", lat)
# Geometric Heliocentric Latitude: -0.9735
print_me("Radius vector", r)
# Radius vector: 29.93966
Compute the geocentric position for 1992/12/20:
epoch = Epoch(1992, 12, 20.0)
ra, dec, elon = Neptune.geocentric_position(epoch)
print_me("Right ascension", ra.ra_str(n_dec=1))
# Right ascension: 19h 17' 14.5''
print_me("Declination", dec.dms_str(n_dec=1))
# Declination: -21d 34' 15.1''
print_me("Elongation", elon.dms_str(n_dec=1))
# Elongation: 19d 44' 59.6''
Print mean orbital elements for Neptune at 2065.6.24:
epoch = Epoch(2065, 6, 24.0)
l, a, e, i, ome, arg = Neptune.orbital_elements_mean_equinox(epoch)
print_me("Mean longitude of the planet", round(l, 6))
# Mean longitude of the planet: 88.321947
print_me("Semimajor axis of the orbit (UA)", round(a, 8))
# Semimajor axis of the orbit (UA): 30.11038676
print_me("Eccentricity of the orbit", round(e, 7))
# Eccentricity of the orbit: 0.0094597
print_me("Inclination on plane of the ecliptic", round(i, 6))
# Inclination on plane of the ecliptic: 1.763855
print_me("Longitude of the ascending node", round(ome, 5))
# Longitude of the ascending node: 132.46986
print_me("Argument of the perihelion", round(arg, 6))
# Argument of the perihelion: -83.415521
Compute the time of the conjunction close to 1993/10/1:
epoch = Epoch(1993, 10, 1.0)
conj = Neptune.conjunction(epoch)
y, m, d = conj.get_date()
d = round(d, 4)
date = "{}/{}/{}".format(y, m, d)
print_me("Conjunction date", date)
# Conjunction date: 1994/1/11.3057
Compute the time of the opposition close to 1846/8/1:
epoch = Epoch(1846, 8, 1)
oppo = Neptune.opposition(epoch)
y, m, d = oppo.get_date()
d = round(d, 4)
date = "{}/{}/{}".format(y, m, d)
print_me("Opposition date", date)
# Opposition date: 1846/8/20.1623