def get_radec_cols(cat):

    """Return names of the RA and Dec columns for this catalog.

    Parameters
    ----------
    cat : Astropy Table object
        catalog to extract RA and Dec columns from

    Returns
    -------
    racol : Astropy.table.column object
        RA column values

    deccol : Astropy.table.column object
        Dec column values
    """

    # create a column name dictionary
    d = dict([(x, 1) for x in cat.colnames])
    for v in ["ra", "RA", "ALPHA_J2000", "alpha_j2000"]:
        if v in d:
            racol = v
            break
    else:
        raise ValueError("RA column not found in", " ".join(cat.colnames))
    for v in ["dec", "DEC", "Dec", "DELTA_J2000", "delta_j2000"]:
        if v in d:
            deccol = v
            break
    else:
        raise ValueError("RA column not found in", " ".join(cat.colnames))
    return racol, deccol