Observer's guide
About NGC 6494
NGC 6494 (M23) is catalogued as an open cluster in Sagittarius. Its J2000 position is RA 17:57:04.77, Dec -18:59:07.2, corresponding to 269.2371 degrees RA and -18.9869 degrees Dec. The local catalogue places it about 2,150 light-years away. Its referenced angular extent is approximately 35 by 35 arcminutes.
Observing tips
StarWatchr rates this as an easy target at magnitude 6.9. It is associated with summer observing, with midnight placement typically strongest around June. From 52 degrees north its theoretical meridian altitude is about 19 degrees; local horizons and the live altitude chart determine the practical window.
A small telescope under reasonably dark skies is a good starting point; use the live altitude chart to choose its highest point.
What to expect
The SIMBAD classification for the matched source is OpC. A published radial velocity value is -31.7 km/s. The SIMBAD record currently connects it to 149 bibliographic references.
Its roughly 35 arcminute span suits a medium field of view. Use the listed 35 by 35 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.