2016 Nov. 18 ~ The Milky Way in the constellation Cygnus [WITH LABELS]

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Photographed at Algonquin Provincial Park, Ontario, Canada

(285 km by road north of Toronto)

* Temperature 11 degrees C.

 

* Total exposure time: 10 minutes.

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Description:

 

Our home galaxy, the Milky Way, runs through the constellation Cygnus (the Swan) high in the northern hemisphere summer and autumn sky. Dense clouds of stars are obscured in places by winding lanes of dark foreground gas.

 

The red appearance of glowing clouds of hydrogen gas, the colours of which cannot be seen with the human eye, are revealed by the digital camera's sensor in long exposure photographs.

 

One of the most distinctive gas clouds is the aptly named "North America Nebula", to the left of centre. For a close-up view of this nebula made with a 400 mm lens, click here:

www.flickr.com/photos/97587627@N06/19933485213

 

To the right of the North America Nebula, and just left of centre, is a complex patch of red hydrogen gas surrounding the bright star Sadr (Gamma Cygni). For a close-up of this region made with a 540 mm focal length telescope in Sept. 2016, click here:

www.flickr.com/photos/97587627@N06/31156465551

 

For a version of this photo WITHOUT labels, click on the LEFT side of your screen, or here:

www.flickr.com/photos/97587627@N06/31156349001

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Technical information:

 

Sigma 50 mm f/1.4 DG HSM ART lens on Nikon D810a camera body, mounted on Astrophysics 1100GTO equatorial mount with a Kirk Enterprises ball head

 

Ten stacked frames; each frame:

50 mm focal length

ISO 2500; 1 minute exposure at f/4; unguided

(with LENR - long exposure noise reduction)

 

Subframes registered in RegiStar;

Stacked and processed in Photoshop CS6 (brightness, contrast, levels, colour balance)

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Done