plot_positions_solo.py

import matplotlib.pyplot as plt
import numpy as np 

from sunpy.coordinates import get_horizons_coord
from sunpy.time import parse_time

from astropy import units as u
import astropy.constants as const


def plot_positions_hgs(obstime):
    """
    Function to plot the positions of SoLO and Earth with respect to the Sun.

    obstime : `str`
    """
    obstime = parse_time(obstime)
    solo_pos = get_horizons_coord("SOLO", obstime)
    earth_pos = get_horizons_coord("399", obstime)
    sun_pos = get_horizons_coord("10", obstime)

    fig = plt.figure(figsize=(6, 6))
    ax = fig.add_subplot(projection="polar")

    ax.plot(solo_pos.lon.to(u.rad), solo_pos.radius.to(u.AU), marker='o', label="SoLO",  color='tab:blue', ms=10)
    ax.plot(earth_pos.lon.to(u.rad), earth_pos.radius.to(u.AU), marker='o', color='g', label="Earth", ms=10)

    ax.plot([solo_pos.lon.to_value(u.rad), sun_pos.lon.to_value(u.rad)], 
        [solo_pos.radius.to_value(u.AU), sun_pos.radius.to_value(u.AU)], color='tab:blue', ls="dashed")

    ax.plot([earth_pos.lon.to_value(u.rad), sun_pos.lon.to_value(u.rad)], 
        [earth_pos.radius.to_value(u.AU), sun_pos.radius.to_value(u.AU)], color='green', ls="dashed")

    ax.plot(sun_pos.lon.to(u.rad), sun_pos.radius.to(u.AU), marker='o', color='y', label="Sun",  ms=14)
    ax.set_theta_zero_location("S")
    _ = ax.set_yticklabels([])
    ax.legend(bbox_to_anchor=(1.3, 0.9))
    ax.set_rlim(0, 1.3)
    ax.set_title("Positions in Heliographic StonyHurst")
    ax.text(np.deg2rad(160), 1.4, "{:s}".format(obstime.strftime("%Y-%m-%d %H:%M")))
    plt.tight_layout()

    plt.show()