Messier 8: 'The Lagoon Nebula'
Object types:Diffuse Nebula
Constellation: Sagittarius
Date: 2007-05-22
Location: Postalm/Austria (1300m)
Telescope: TMB 80/480 (3.1" Apo f=480mm) + 0.8 TV reducer/flattener
Camera: Starlight XPress SXV-H9
Astronomik H-alpha filter (13nm)
Image type: SII
Binning: 1x1
Exposure time: H 5x10m
Exposure time total: 50m
Notes: -
Cluster NGC 6530 discovered by Flamsteed about 1680. Lagoon Nebula discovered by Le Gentil in 1747.
As often for diffuse nebulae, the cluster of young stars which has formed from the nebula's material was discovered first: In this case, the young open cluster NGC 6530 in the Eastern half of M8 was discovered by John Flamsteed about 1680, and again seen by Philippe Loys de Chéseaux in 1746, before Guillaume Le Gentil found the nebula in 1747. Abbe Nicholas Louis de la Caille has cataloged it in his 1751-52 compilation as Lacaille III.14. When Charles Messier cataloged this object on May 23, 1764, he also primarily described the cluster, and mentioned the nebula separately as surrounding the star 9 Sagittarii; his original position is closer to the modern position of the cluster than to that of the nebula. Nevertheless, it is the nebula which is now generally regarded as "Messier 8."
http://seds.lpl.arizona.edu/messier/m/m008.html