pub fn angular_separation_coords(
a_lon_lat_deg: (f64, f64),
b_lon_lat_deg: (f64, f64),
) -> Result<f64, AngleError>Expand description
On-sky angle (degrees) between two (lon, lat) / (RA, Dec) pairs in
degrees. The second tuple component is the latitude or declination in
[-90, 90].