There is now also a CBET about the new interstellar #comet 3I/ATLAS: http://www.cbat.eps.harvard.edu/iau/cbet/005500/CBET005578.txt - it comes with an even more precise orbit based on astrometry back to 5 June and predicts 13th magnitude with 60° elongation after perihelion in November. The current magnitude is about 17.7.