Lacaille I.11 (NGC 6634)

During his journey to the Cape of Good Hope in 1751-52, Nicholas Louis de Lacaille observed this "nebulous" object in his 0.5-inch telescope, and included it in his Catalog of Nebulae in the Southern Sky.

When Charles Messier looked for this object on July 27, 1764, he didn't find it. But when he observed again in 1780, he found both M69 and M70 close to Lacaille's position. He thought that with M69, he had rediscovered Lac I.11. Many authors and historians of the Lacaille Catalog have since followed Messier with this identification.
However, as Glen Cozens of Australia has pointed out, this is probably not the case, for the following reasons:

In his GC, John Herschel did not follow Messier's identification but assigned an own GC number to Lac I.11, GC 5076, which consequently found its way into the NGC (NGC 6634).

Thanks to Glen Cozens for contributing his identification!

  • NGC Online data for NGC 6634
  • The "missing" Lacaille objects


    Hartmut Frommert
    Christine Kronberg
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    Last Modification: July 20, 2011