def test_comet():
text = (b' CJ95O010 1997 03 29.6333 0.916241 0.994928 130.6448'
b' 283.3593 88.9908 20200224 -2.0 4.0 C/1995 O1 (Hale-Bopp)'
b' MPC106342\n')
ts = load.timescale()
t = ts.utc(2020, 5, 31)
eph = load('de421.bsp')
e = eph['earth'].at(t)
for loader in mpc.load_comets_dataframe, mpc.load_comets_dataframe_slow:
df = loader(BytesIO(text))
row = df.iloc[0]
k = mpc.comet_orbit(row, ts, GM_SUN)
p = e.observe(eph['sun'] + k)
ra, dec, distance = p.radec()
# The file authorities/mpc-hale-bopp in the repository is the
# source of these angles. TODO: can we tighten this bound and
# drive it to fractions of an arcsecond?
ra_want = Angle(hours=(23, 59, 16.6))
dec_want = Angle(degrees=(-84, 46, 58))
assert abs(ra_want.arcseconds() - ra.arcseconds()) < 2.0
assert abs(dec_want.arcseconds() - dec.arcseconds()) < 0.2
assert abs(distance.au - 43.266) < 0.0005
assert k.target == 'C/1995 O1 (Hale-Bopp)'
def test_arcminutes_and_arcseconds_and_mas():
angle = Angle(degrees=1.0)
assert angle.arcminutes() == 60
assert angle.arcseconds() == 60 * 60
assert angle.mas() == 60 * 60 * 1000