M 6  -  Butterfly Cluster

50% resolution (900kB)

Object identification (900kB)

Image with NP101 (f=540mm)

Object data of M6

Object type: open cluster (II3r)
Size: 25'
Magnitude: 4.2 mag
Constellation: Sco
Distance: 1,600 Ly
Notes: M6 is a young open star cluster in the constellation Scorpius (age: 100 million years).

The brightest star in this cluster is the variable star BM Scorpii, a yellow supergiant (spectral type K3). BM Sco is a semiregular variable star, with its apparent magnitude varying between mag 5.5 and 7.

Many open star clusters can be found in the above image:

  • M6
  • NGC6374, NGC6404, NGC6416, NGC6425
  • Trumpler 27, Trumpler 28

Exposure data

Date: 2009-09-12
Location: La Palma / Spain (1700m)
Telescope: Rubinar300 (2.5" Maksutov Cassegrain f=300mm)
Camera: EOS1000D (ISO400)
Mount: Astrotrac TT320X
Exposure time: 47x2m
Exposure time total: 1h 34m