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Exposure data

Telescopes:    4.5" Newton f=440mm + Vixen R200SS (8" Newton 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
 
Object data of M 20

Object type:    Emission and reflection nebula
Size:    28'
Magnitude:     6.3 mag
Constellation:     Sagittarius
Distance:     5200 Ly
 
Object data of M 21

Object type:    Open cluster (l 3 m)
Size:    13'
Magnitude:    6.5 mag
Constellation:    Sagittarius
Distance:    4250 Ly