M20

The Trifid Nebula in Sagittarius

Uploaded 5/12/02

An impressive mixture of both reflection and emission nebulosities, this large object is also cross cut by thin obscuring dust lanes giving it its namesake. The red portion is over 17 arcmins in size, and spills over slightly my 15 arcminute field of view. The battery of four central stars powers the nebula, surrounded by a bluish haze. Thought to lie at the same distance of the nearby Lagoon Nebula, the object has changed little in appearance over the last century of telescopic observation. This object is another example of a Stromgren Sphere. The UV from the hot central stars goes only so far out in the nebulous cloud, then stops. This is the boundary where the red ends on the outside of the nebula and the blue outer halo begins.

Instrument:  12.5" f/5 Home made Newtonian
Platform:  Astrophysics 1200 QMD
CCD Camera:  SBIG ST7E w/Enhanced Cooling
Exposure:  LRGB = 60:20:20:20 (RGB Binned 2x2)
RGB Combine Ratio:  1: .95: 1.8
Filters:  RGB Tricolor
Location:  Payson, Arizona
Elevation:  5150 ft.
Sky:  Seeing FMHW = 2.8 arcsec, Transparency 8/10
Outside Temperature:  10 C
CCD Temperature:  -25 C
Processing:  Maxim DL, Photoshop, AIP4WIN, PW Pro.

 

 

 
 


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