LAGOON NEBULA OBSERVATION LOG

These are the images of the Lagoon Nebula (Messier 8/NGC 6523) (different edits) using the observatory’s Meade LX850 16-inch SCT, Skywatcher EQ8 mount (guided) and unmodified Canon EOS 700D taken by Al Sadeem Astronomy’s director Alejandro Q. Palado last May 9, 2018.

The Lagoon Nebula is a large emission nebula (an interstellar cloud of gas and dust being ionized by nearby hot, young stars, emitting different wavelengths of light) in the prominent constellation Sagittarius (the archer). It was by the Italian astronomer Giovanni Battista Hodierna in 1654 and later added to the Messier catalog by Charles Messier himself on May 23, 1764. It is about 4000-6000 light years away from Earth which spans about 110×50 light-years of space.

The nebula’s name was derived from its lagoon-shaped cloud observed to the left of a star cluster known as NGC 6530 (when seen with a diagonal, inverting the image). Further observations found that it is an ongoing active star formation stage wherein several young, hot bluish stars are being formed mostly in the near-central region, illuminating the nebula. The English astronomer William Herschel described the region as the “Hourglass”. This nebula also consists of numerous Bok globules (patches of collapsing dark protostellar gas) which span about 10,000 AU (1.496×10^12 km) across.

Having an apparent magnitude of 6.0, it is barely seen with the naked eye most especially in completely dark skies, away from any light pollution. The Lagoon Nebula can be found just above and to the right of the bright star Kaus Borealis, the tip of the teapot asterism. Using binoculars and small telescopes, it would look gray to the naked eye and appears pink in long-exposure color photographs. The reason for the difference is that the eye is not sensitive enough to detect different colors in low-level light compared to a camera which just collecting light in the visible spectra. It is best observed in the summer until fall.