Astropy.coordinates

#!/usr/bin/env python3

from astropy.coordinates import EarthLocation, AltAz, SkyCoord
from astropy.time import Time
import astropy.units as u

#
# Sternwarte Eschenberg
#
location = EarthLocation(
              lat    =  47.4721981112  * u.deg,
              lon    =   8.7397303744  * u.deg,
              height = 340             * u.m)

#
# Time of observation
#
obstime = Time('2026-08-16 22:00:00')

# Example: convert a sky position from Alt/Az to RA/Dec
altaz = SkyCoord(
           alt      =  45 * u.deg,
           az       = 180 * u.deg,
           obstime  = obstime,
           location = location,
           frame    ='altaz')

#
# Transform to ICRS (RA, Dec)
#
icrs = altaz.transform_to('icrs')

print(icrs.ra, icrs.dec)