Observer's guide
About Butterfly Cluster
Butterfly Cluster (M6) is catalogued as an open cluster in Scorpius. Its J2000 position is RA 17:40:20.75, Dec -32:15:15.0, corresponding to 265.0692 degrees RA and -32.2419 degrees Dec. The local catalogue places it about 2,000 light-years away. Its referenced angular extent is approximately 20 by 20 arcminutes.
Observing tips
StarWatchr rates this as an easy target at magnitude 5.3. It is associated with summer observing, with midnight placement typically strongest around June. From 52 degrees north its theoretical meridian altitude is about 5.8 degrees; local horizons and the live altitude chart determine the practical window.
Its brightness makes it a practical binocular or small-telescope candidate when it is well above the horizon.
What to expect
The SIMBAD classification for the matched source is OpC. A published radial velocity value is -7.4 km/s. The SIMBAD record currently connects it to 241 bibliographic references.
Its roughly 20 arcminute span suits a medium field of view. Use the listed 20 by 20 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.