Open cluster · Scorpius
M6 Butterfly Cluster
Also known as: NGC 6405
mag 4.215′ across
About
M6, the Butterfly Cluster, is an open cluster of magnitude 4.2 in Scorpius, about 15′ across.
How to find it
- M6 is in the constellation Scorpius.
- Best evenings: around early August it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from south of 48° N.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesA hazy patch or a knot of faint stars from a dark site.
- Binoculars (10×50)A small knot of stars, partly resolved.
- Telescope (6–8 inch)Dozens of stars, many sharp and some coloured.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | M6, NGC 6405 |
|---|---|
| Type | Open cluster |
| Magnitude | 4.2The smaller the number, the brighter. |
| Apparent size | 15′the full Moon is 31′ across |
| Constellation | Scorpius |
| Right ascension (J2000) | 17h 40m 20.8s |
| Declination (J2000) | −32° 15′ 15″ |
More in Scorpius
Sources and credits
Catalog data: OpenNGC by Mattia Verga, CC BY-SA 4.0, and d3-celestial by Olaf Frohn, BSD 3-Clause. All data sources →