NGC 869 & NGC 884 (Gary Imm)

NGC 869 & NGC 884

This object is a double star cluster located 7000 light years away in the constellation of Perseus at a declination of +57 degrees. The clusters each span about 20 arc-minutes in our apparent view, which corresponds to an actual diameter of about 40 light years.

NGC 884 is left and NGC 869 is right. The field is dominated by bright white stars but there are also numerous orange stars sprinkled throughout each cluster. Each cluster contains about 200 stars.

It is fascinating to me how this wonderful object never made the Messier Catalog. I always wondered about that. I recently stumbled upon an excellent explanation by Steven James O’Meara. According to O’Meara, “The Double Cluster is the only celestial object visible from Messier's latitude and known since classical times that is not included in the comet hunter's original list of 45 objects (of the 110 total objects). So why not include the Double Cluster? From Messier's latitude of nearly 50° N, the Double Cluster is circumpolar and never sets. Its far northerly declination of nearly +60° places it well outside of the comet haystack during most of the year.” The “comet haystack” is that part of the sky centered on the ecliptic near sunset or sunrise, where comet hunters search for comets.

So the Double Cluster was not included in Messier's list simply because, based on its northerly location in the sky, Messier never felt it would be confused with a comet, which was the sole criteria for the objects on his list. Even though objects like M31 seem like they never would be confused with a comet in the dark sky, they have often been confused with comets at twilight when they fall in the haystack area.

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Status	Advanced success
Started	...
Astrometry.net job	4091023
PixInsight job	PTNZ7PS6W0TDLAOJUAZGQ9UVJNOXUXK5
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	02h20m33s.645
RA (top/left)	02h27m38s.441
RA (top/right)	02h13m44s.307
RA (bottom/right)	02h13m42s.299
RA (bottom/left)	02h27m08s.362

Dec (center)	+57°09′27″.57
Dec (top/left)	+57°45′01″.76
Dec (top/right)	+57°48′17″.34
Dec (bottom/right)	+56°32′26″.41
Dec (bottom/left)	+56°29′18″.19

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NGC 869 & NGC 884

NGC 869 & NGC 884

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NGC 869 & NGC 884

NGC 869 & NGC 884

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