Use Astropy to manipulate HYG database

bright_stars.py

from astropy.coordinates import SkyCoord, Angle, Distance
from astropy.table import Table
from astropy import units as u


def main():

    # Read stars data into an astropy table
    # https://www.astronexus.com/downloads/catalogs/hygdata_v3.csv.gz
    stars_table = Table.read("hygdata_v3.csv")

    # Get positions in ICRS
    stars_positions_icrs = SkyCoord(
        ra=Angle(stars_table["ra"], unit=u.deg),
        dec=Angle(stars_table["dec"], unit=u.deg),
        distance=Distance(stars_table["dist"], unit=u.parsec),
        frame="icrs",
        copy=False,
    )

    # Convert to galactocentric positions and retrieve the XYZ coordinates
    stars_positions_galactocentric = stars_positions_icrs.galactocentric
    x, y, z = [getattr(stars_positions_galactocentric, axis) for axis in "xyz"]


if __name__ == "__main__":
    main()