2019 Aug. 5 ~ Star clusters and nebulae in the constellations Cassiopeia & Cepheus
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Photographed at Algonquin Provincial Park, Ontario, Canada
(285 km by road north of Toronto)
between 00.59 and 01.29 EDT
* Altitude of centre of frame at time of exposures: ~57°
* Temperature 18° C.
* Total exposure time: 12 minutes
* 660 mm focal length telescope
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Description:
Open stars clusters are agglomerations of stars that are loosely bound together gravitationally. Because cluster members are quite far apart, the gravitational attraction among them is weak, and as a result they drift apart after several millions of years.
There are more than 1,100 known open clusters of stars in our Milky Way galaxy. Of these, about 10% are located in the constellation Cassiopeia (which is the 25th largest of the 88 constellations).
In this view we see five clusters of various sizes, ages and distances from our solar system, and brightnesses as seen from planet Earth. The largest of these, M52 at upper left, can be easily seen in binoculars as faint fuzzy patch, and is a beautiful sight in a modest telescope.
In addition, several red-pink clouds of glowing ionized hydrogen gas appear in this photo. The largest of these is the "Bubble Nebula" (NGC 7635) left of centre. Per Wikipedia: "The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star ... The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow."
For a version of this image with labels, click on the RIGHT side of your screen, or click here:
www.flickr.com/photos/97587627@N06/49238262581
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Technical information:
Nikon D810a camera body on Tele Vue 127is (127 mm - 5" - diameter) apochromatic astrograph, mounted on Astrophysics 1100GTO equatorial mount
Twelve stacked subframes; each frame:
ISO 6400; 1 minute exposure at f/5.2, unguided
(with LENR - long exposure noise reduction)
Subframes stacked in RegiStar;
Processed in Photoshop CS6 (brightness / contrast, levels, colour balance)
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2019 Aug. 5 ~ Star clusters and nebulae in the constellations Cassiopeia & Cepheus
***************************************************************************
Photographed at Algonquin Provincial Park, Ontario, Canada
(285 km by road north of Toronto)
between 00.59 and 01.29 EDT
* Altitude of centre of frame at time of exposures: ~57°
* Temperature 18° C.
* Total exposure time: 12 minutes
* 660 mm focal length telescope
___________________________________________
Description:
Open stars clusters are agglomerations of stars that are loosely bound together gravitationally. Because cluster members are quite far apart, the gravitational attraction among them is weak, and as a result they drift apart after several millions of years.
There are more than 1,100 known open clusters of stars in our Milky Way galaxy. Of these, about 10% are located in the constellation Cassiopeia (which is the 25th largest of the 88 constellations).
In this view we see five clusters of various sizes, ages and distances from our solar system, and brightnesses as seen from planet Earth. The largest of these, M52 at upper left, can be easily seen in binoculars as faint fuzzy patch, and is a beautiful sight in a modest telescope.
In addition, several red-pink clouds of glowing ionized hydrogen gas appear in this photo. The largest of these is the "Bubble Nebula" (NGC 7635) left of centre. Per Wikipedia: "The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star ... The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow."
For a version of this image with labels, click on the RIGHT side of your screen, or click here:
www.flickr.com/photos/97587627@N06/49238262581
___________________________________________
Technical information:
Nikon D810a camera body on Tele Vue 127is (127 mm - 5" - diameter) apochromatic astrograph, mounted on Astrophysics 1100GTO equatorial mount
Twelve stacked subframes; each frame:
ISO 6400; 1 minute exposure at f/5.2, unguided
(with LENR - long exposure noise reduction)
Subframes stacked in RegiStar;
Processed in Photoshop CS6 (brightness / contrast, levels, colour balance)
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