The Caldwell Objects

Appendix B Why Messier Did
N o t i n c l u d e t h e D o u b l e
ONE MYSTERY THAT STILL HAUNTS THE HALLS of
astronomy is why the 18th-century French comet
hunter Charles Messier did not include the
Double Cluster in his famous catalog. "This
splendid object. . . was certainly known in his
day," Robert Burnham Jr. comments in his
Celestial Handbook, "and he included other bright
clusters such as Praesepe and the Pleiades." So
why not the Double Cluster?
I believe Messier had a very logical reason to
omit it. But first a powerful myth must be
dispelled.
The Messier Catalog is not a list of the best or
the brightest deep-sky objects in the heavens.
This cannot be said enough. It is not a
manifest of celestial superlatives. But who hasn't
loosely described the Messier objects as the finest
in the heavens? On the jacket of The Messier
Album, by John H. Mallas and Evered Kreimer,
no less an authority than Harvard University
astronomer Owen Gingerich encourages readers
to "find a telescope and a clear night, and . . .
begin the chase of the most spectacular sidereal
objects of the northern skies" (emphasis mine).
Without question, the Messier Catalog contains
some of the most spectacular deep-sky
objects visible in small telescopes. But their
inclusion in the catalog is largely circumstantial.
Messier never intended to create a list of
Appendix Β 449