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NGC 6994

Right Ascension20h 59m 50s
Declination-12° 33' 56"
Brightest StarBD-13 5809 (BWM 1)
Optimum VisibilityAugust
NotesThis group of four stars was originally taken by Messier to be an open cluster, perhaps with associated nebulosity, and so he placed it in his catalogue as the star cluster M73. These stars are now known to be unrelated to one another, and so M73 is more properly classified as an extremely small and faint asterism.
Map of M73 in Aquarius Map of M73 in Aquarius

Since Messier's time, there has been controversy over the status of this formation, and specifically about whether or not it represents a cluster of related stars. It is now generally considered that they do not. The stars' distances from Earth, and their respective proper motions, are quite different from one another. Messier's 'cluster', then, actually appears to be no more than an asterism, a group of stars on the same line of sight from Earth. The 'BWM' designations shown on this map relate to the Bassino Waldhausen Martinez catalogue of 144 stars in this small region of the sky.


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