The Butterfly Cluster (M6) in Scorpius




A 70-minute image of the “open” star cluster M6 in the constellation Scorpius. This cluster lies along the galactic equator on the celestial sphere, near the center of our Milky Way galaxy. As a result, the background reveals a rich concentration of countless stars due to the much greater density of stars along the plane of the galaxy. However, the cluster is only 1,600 light years from Earth, far short of the actual center of our galaxy some 25,000 light years away. So, while M6 appears to be embedded in the core of our galaxy, it is in fact more than 20,000 light years away.

 M6 contains about 80 stars spread over an area 12 light years wide. Most of the stars are “B class” blue giants, as clearly seen in this image. However, the brightest star in the cluster is the anomalous reddish star. This is BM Scorpii, a “K class” red-giant star millions of times larger than our Sun. Its reddish color is due to its low surface temperature resulting from the prodigious expansion of the star in the red-giant stage. 

M6 is often called the “Butterfly Cluster,” owing to what some perceive to be its butterfly shape. 






Image Name:

The Butterfly Cluster (M6) in Scorpius

Date Taken:

June 20, 2015

Location Taken:

Siding Spring Observatory, NSW Australia

Conditions of Location:

Equipment Used:

Planewave 20" corrected Dall-Kirkham telescope, FLI PL09000 camera

Processing Used:

9 x 3 minutes luminance, 7 x 2 minutes RGB, for a total exposure of 70 minutes

Distance from Location:

1,600 light years



Other Link:

Leave a Reply

Your email address will not be published. Required fields are marked * © Richard Hammar 2004-2016 |
Website by Lucas Cornwell Hit Counter - Login
Follow on Bloglovin