2025 Aug. 16 ~ The Pleaides (Seven Sisters, M45) from downtown Toronto; mid-twilight [WITH LABELS]

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Photographed at 05.01 EDT from the football pitch at Northern Secondary School in mid-town Toronto, Ontario, Canada

 

THIS PHOTO WAS JUST FOR FUN, to see what this well-known star cluster would look like from a terrible astrophotography location!

 

Sun 13.5° below the horizon

Altitude of M45 at time of exposures: 54.6°

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Description:

 

This most famous of all open star clusters is readily visible to the unaided eye even in the middle of a light-polluted city. Morning twilight was starting to creep into the eastern sky when I grabbed the subframes to make this image, so the sky was starting to turn a little blue.

 

Even though the subframes from which this stacked images were made were only 10 seconds in length, at ISO 200, stars to 14th magnitude can be seen if you look carefully.

 

For a version of this photo WITHOUT STAR LABELS, click on your screen to the LEFT of the photo, or click here:

www.flickr.com/photos/97587627@N06/54787415517

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Technical information:

 

Nikon D810a camera body on Tele Vue 127is (127 mm - 5" - diameter) apochromatic refracting telescope, mounted on a Sky-Watcher EQ6-R PRO SynScan mount

 

Eleven stacked frames; each frame:

660 mm focal length

ISO 200; 10 sec. at f/5.2; unguided

(with LENR - long exposure noise reduction)

 

Subframes registered in DeepSkyStacker;

Processed in Photoshop CS6

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Done