But­ter­fly Cluster (M6) in Scorpius

Open Clusters - M6 Cluster in Scorpius Astrophotography Martin Rusterholz

The But­ter­fly Cluster (Messi­er 6, NGC 6405) is an open cluster of stars in the south­ern con­stel­la­tion of Scorpi­us. Its name derives from the vague resemb­lance of its shape to a but­ter­fly. The cluster is estim­ated to be 94.2 mil­lion years old and lies at a dis­tance of about 1’500 light years. 120 stars, ran­ging down to visu­al mag­nitude 15.1, have been iden­ti­fied as most likely cluster mem­bers. Most of the bright stars in this cluster are hot, blue B‑type stars but the bright­est mem­ber is a K‑type orange giant star, BM Scorpii.

To cre­ate the image, Ha data have been mixed into the red chan­nel to bring out some more details of the struc­ture. North is up in the image.

[descrip­tion from wikipedia]


Taka­hashi FSQ-106EDX III
10Micron GM2000 HPSII
Astro­don Gen2
L(HaR)GB 305:(520:145):115:115 min.
San Pedro de Atacama — Chile
© Mar­tin Ruster­holz, Astrophotographer

Find­er Chart But­ter­fly Cluster (M6) in Scorpuis

M6 in Scorpius Sky Chart Astrophotography Martin Rusterholz

Image cre­ated by Skychart

About Me

Hello, my name is Martin Rusterholz. I’m a Swiss amateur astrophotographer living near Zurich, the biggest town in Switzerland. My interest in astronomy started when I was 16. At that time, I built my first Newtonian telescope and mount. I studied physics at the Swiss Federal Institute of Technology (ETH) which was the only study including at least some aspects of astronomy and astrophysics. “Looking at the nights sky is an experience touching everybody deeply inside, something common to all human beings independent to the language spoken by the individuals”. Deep-sky astrophotography is my passion.