def readLine(line):
	""" Reads out a line from the ephemeris file, returns time, position and position angle. 
		
		Arguments:
			line: [string] Ephemeris line.

		Return:
			param_tup: [tuple of 4 elements] Tuple containing the date [string], RA, Dec and PA [floats]. 
	"""

	# Extract the data as strings
	date_str = line[8:13]
	ra_str = line[17:24]
	dec_str = line[26:33]
	pa = line[60:65]

	# print(line)

	# print(date_str, ra_str, dec_str, pa)

	# Convert RA string to degrees
	ra_deg = float(ra_str) * 15

	# Determine the Dec sign
	sign = dec_str[0]

	# Convert Dec string to degrees
	dec_deg = float(dec_str[0:])

	if sign == '-':
		dec_deg *= -1

	# Convert PA string to float
	pa_deg = float(pa)

	param_tup = (date_str, ra_deg, dec_deg, pa_deg)

	return param_tup