M 6  -  Butterfly Cluster

Full resolution (1600x1200 px  780kB)

Object identification in 50% resolution (280kB)

Widefield image (f=300mm)

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.

Exposure data

Date: 2009-09-12 + 14 +15
Location: La Palma / Spain (1700m)
Telescope: TeleVue NP101 (4" Apo f=540mm)
Camera: ST2000XM with CFW8 and Baader Filters
Binning: L 1x1 / RGB 1x1
Exposure time: L 36x2m / R 6x5m / G 6x5m / B 6x5m
Exposure time total: 2h 42m
Notes: bad seeing and high clouds during luminance exposures