The Lagoon Nebula (M8), The Trifid Nebula (M20) and M21 in Sagittarius

Note: this is the full resolution image and as such it might be difficult to view in your browser; right-click the image and select View Image to make it fit in your browser window.

This was data that I was capturing while working on another mosaic.

This was also my first time in blending hydrogen alpha data in to the luminance, as well as into the red and blue channels. I think it has turned out nicely.

The Lagoon Nebula is a magnificent object, easily visible to the naked eye in decent skies as a hazy patch. It is a bright and large emission nebula with an embedded open cluster. This cluster of young stars is heating the nebula's gas and causing it to emit light. In binoculars, the dark lane (the lagoon) that divides the nebula's brighter regions and gives it its name becomes apparent. A small telescope begins to reveal this object's intricate folds and dark regions amongst brighter areas. Dark 'Bok globules' in the nebula mark dense clouds of gas and dust which are the site of star formation.

The Trifid Nebula gets its name from the rifts of dark dusty lanes that trisect its southern region. The Trifid Nebula lies in a rich part of the Milky Way, with M21 (an open cluster) close by visible in the same field of view as the Lagoon Nebula when seen through binoculars. This trio makes a stunning site and is typically best viewed at low power through a telescope. M20 and M8 may be physically connected, although, this is uncertain. The Trifid Nebula is a hot red emission nebula of hydrogen gas surrounded by a beautiful blue glow of a reflection nebula made up of dust grains.

M21 is a cluster of bright stars that lie north of the Trifid Nebula. It contains about 60 stars that are readily visible in a small telescope. M21 has a strong concentration of stars towards its centre and makes a great site through binoculars. In a larger telescope, a "diamond ring" of 10 or so stars become visible. This cluster is considered extremely young, being just 5 million years old.

This is the culmination of 20 hours of data imaged over 11 nights in July, 2018.

Target: The Lagoon Nebula (M8), The Trifid Nebula (M20) and M21 in Sagittarius
Date(s): 2018; July: 2nd, 3rd, 4th, 5th, 8th, 9th, 10th, 11th, 13th, 14th and 15th
Location: Gordon, ACT, Australia
Detector: SBIG STL-11000M at -20 degrees Celsius
Telescope: Takahashi FSQ-106N
Focal length: 530mm
Mount: Losmandy G-11 (Gemini)
Guide scope: Takahashi FS-60CB
Guide camera: SBIG Remote Guide Head
Exposure: Nebula L(Ha)R(Ha)GB(Ha) (120 120 120 120 720); total: 20 hours in 300 second subexposures for LRGB and 1800 second subexposures for Ha
Exposure: LRGBHa bin 1x1
Software: MaxIm DL 5, CCD Commander, FocusMax, PinPoint, PixInsight and Photoshop