def coord_to_str(ra, dec):
    """Transfer coord into str

    Args:
        ra (float): RA in deg
        dec (float): DEC in deg

    Returns:
        ra_str (str): RA str
        dec_str (str): DEC str
    """
    rah = int(ra / 15)
    ram = int((ra * 60 / 15 - rah * 60))
    ras = ra * 240 - rah * 3600 - ram * 60
    decd = int(dec)
    decm = int(dec * 60 - decd * 60)
    decs = dec * 3600 - decd * 3600 - decm * 60
    ra_str = "{0:2d}:{1:0>2d}:{2:0>5.2f}".format(rah, ram, ras)
    dec_str = "{0:3d}:{1:0>2d}:{2:0>5.2f}".format(decd, decm, decs)
    return ra_str, dec_str