M 20 + M 21
Exposure data
Object data of M 20
Telescope: 4.5″ Newton f=440mm + Vixen R200SS f=800mm
Camera: SBIG ST2000XM
Filters: SBIG LRGB
Exposure times: L: 30x3min + 12x5min R: 8x3min + 2x5min G: 8x3min + 2x5min B: 10x2min
Exposure time total: 3h 58min
Mount: Vixen New Atlux
Location: Erdweg/Germany (500m)
Date: 2005-07-04 + 2010-07-02
Camera: SBIG ST2000XM
Filters: SBIG LRGB
Exposure times: L: 30x3min + 12x5min R: 8x3min + 2x5min G: 8x3min + 2x5min B: 10x2min
Exposure time total: 3h 58min
Mount: Vixen New Atlux
Location: Erdweg/Germany (500m)
Date: 2005-07-04 + 2010-07-02
Object type: Emission and reflection nebula
Size: 28′
Magnitude: 6.3mag
Constellation: Sagittarius
Distance: 5200 Ly
Size: 28′
Magnitude: 6.3mag
Constellation: Sagittarius
Distance: 5200 Ly
Object data of M 21
Object type: Open star cluster (I 3 m)
Size: 13′
Magnitude: 6.5 mag
Constellation: Sagittarius
Distance: 4250 Ly
Size: 13′
Magnitude: 6.5 mag
Constellation: Sagittarius
Distance: 4250 Ly