Binary and Multiple Stars

[M Binary] Click here to view a binary star from Messier's catalog

The icon shows the 4-star system M73.

Binary and multiple stars are common in the universe. Stellar formation results in multiple systems at least as often as in single stars like our Sun, as observations suggest.

Although Messier's catalog was intended to contain only nebulous objects which may be taken for comets, and which we today have found to be clusters, nebulae, or galaxies, and not binary or multiple stars which hardly fall in this category, two have found their way into the Messier catalog: M40 and M73. These entries both were more positional notations, in the case of M40 for a mistake of Hevelius who had reported a nonexistent nebula, and in the case of M73 because Messeier had measured its position together with that of M72.


  • Binary and Multiple Star Catalogs List
  • View "other objects" in Messier's Catalog (those which are not galaxies, nebulae, or clusters)
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    Last Modification: 25 Jan 1998, 14:50 MET