# Uranus 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 = Uranus.geometric_heliocentric_position(epoch)

print_me("Geometric Heliocentric Longitude", lon.to_positive())

# Geometric Heliocentric Longitude: 30.5888

print_me("Geometric Heliocentric Latitude", lat)

# Geometric Heliocentric Latitude: -0.5315

```

Compute the geocentric position for 1992/12/20:

```epoch = Epoch(1992, 12, 20.0)

ra, dec, elon = Uranus.geocentric_position(epoch)

print_me("Right ascension", ra.ra_str(n_dec=1))

# Right ascension: 19h 13' 48.7''

print_me("Declination", dec.dms_str(n_dec=1))

# Declination: -22d 46' 13.0''

print_me("Elongation", elon.dms_str(n_dec=1))

# Elongation: 18d 44' 18.7''
```

Print mean orbital elements for Uranus at 2065.6.24:

```epoch = Epoch(2065, 6, 24.0)

l, a, e, i, ome, arg = Uranus.orbital_elements_mean_equinox(epoch)

print_me("Mean longitude of the planet", round(l, 6))

# Mean longitude of the planet: 235.517526

print_me("Semimajor axis of the orbit (UA)", round(a, 8))

# Semimajor axis of the orbit (UA): 19.21844604

print_me("Eccentricity of the orbit", round(e, 7))

# Eccentricity of the orbit: 0.0463634

print_me("Inclination on plane of the ecliptic", round(i, 6))

# Inclination on plane of the ecliptic: 0.77372

print_me("Longitude of the ascending node", round(ome, 5))

# Longitude of the ascending node: 74.34776

print_me("Argument of the perihelion", round(arg, 6))

# Argument of the perihelion: 99.630865
```

Compute the time of the conjunction close to 1993/10/1:

```epoch = Epoch(1993, 10, 1.0)

conj = Uranus.conjunction(epoch)

y, m, d = conj.get_date()

d = round(d, 4)

date = "{}/{}/{}".format(y, m, d)

print_me("Conjunction date", date)

# Conjunction date: 1994/1/12.7365
```

Compute the time of the opposition close to 1780/12/1:

```epoch = Epoch(1780, 12, 1.0)

oppo = Uranus.opposition(epoch)

y, m, d = oppo.get_date()

d = round(d, 4)

date = "{}/{}/{}".format(y, m, d)

print_me("Opposition date", date)

# Opposition date: 1780/12/17.5998
```

Find the epoch of the Perihelion closer to 1780/1/1:

```epoch = Epoch(1780, 1, 1.0)

e = Uranus.perihelion_aphelion(epoch)

y, m, d = e.get_date()

peri = str(y) + '/' + str(m) + '/' + str(int(d))

print_me("The Perihelion closest to 1780/1/1 happened on", peri)

# The Perihelion closest to 1780/1/1 happened on: 1798/2/26
```

Compute the time of passage through an ascending node:

```epoch = Epoch(2019, 1, 1)

time, r = Uranus.passage_nodes(epoch)

y, m, d = time.get_date()

d = round(d, 1)

print("Time of passage through ascending node: {}/{}/{}".format(y, m, d))

# Time of passage through ascending node: 2028/8/23.2

print("Radius vector at ascending node: {}".format(round(r, 4)))

# Radius vector at ascending node: 19.3201
```