Messier

Messier 92 (also known as NGC6341) is a globular cluster of stars in the northern constellation of Hercules. It was discovered by Johann Elert Bode in 1777, then published in the Jahrbuch during 1779. The cluster was independently rediscovered by Charles Messier on March 18, 1781 and added as the 92nd entry in his catalogue. M92 is at a distance of about 26,700 light-years away from Earth.

M92 is one of the brighter globular clusters in the northern hemisphere, but it is often overlooked by amateur astronomers because of its proximity to the even more spectacular Messier 13. It is visible to the naked eye under very good conditions.

Images by Simon Dawes

Images by Keith Rickard

Messier 71 (also known as NGC 6838) is a globular cluster in the constellation Sagitta. It was discovered by Philippe Loys de Chéseaux in 1745 and included by Charles Messier in his catalogue of comet-like objects in 1780. It was also noted by Koehler at Dresden around 1775.

The star cluster is at a distance of about 12,000 light years away from Earth and spans some 27 light years across. The irregular variable star Z Sagittae is a member of this cluster.

M71 was long thought (until the 1970s) to be a densely packed open cluster, however, modern photometric photometry has detected a short “horizontal branch” in the H-R diagram of M71, which is characteristic of a globular cluster.

Images By Simon Dawes

Images By Debra Holton

Images By Andrew Wilson

Messier 56 (also known as NGC 6779) is a globular cluster in the constellation Lyra. It was discovered by Charles Messier in 1779. M56 is at a distance of about 32,900 light-years from Earth and measures roughly 84 light-years across.
The brightest stars in M56 are of 13th magnitude while it contains only about a dozen known variable stars like V6 (RV Tauri star; period: 90 days) or V1 (Cepheid: 1.510 days); other variable stars are V2 (irregular) and V3 (semiregular).

Images by Simon Dawes

Images by Debra Holton

Images by Andrew Wilson

Messier 53 (also known as NGC 5024) is a globular cluster in the Coma Berenices constellation. It was discovered by Johann Elert Bode in 1775. M53 is one of the more outlying globular clusters, being about 60,000 light-years away from the Galactic Centre, and almost the same distance (about 58,000 light-years) from the Solar system.

Images by Simon Dawes

Images by Andrew Wilson

Globular Cluster M15 (also known as NGC 7078) is a globular cluster in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and included in Charles Messier’s catalogue of comet-like objects in 1764. It is estimated to be 13.2 billion years old, one of the oldest globular clusters.

M15 is at a distance of about 33,600 light-years from Earth. It has an absolute magnitude of -9.2 which translates to a total luminosity of 360,000 times that of the Sun. Messier 15 is one of the most densely packed globulars known in the Milky Way galaxy. 

Images by Simon Dawes

Images by Neil Webster

Messier 14 (also known as NGC 6402) is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier in 1764.

At a distance of about 30,000 light-years, M14 contains several hundred thousand stars. At an apparent magnitude of +7.6 it can be easily observed with binoculars. Medium-sized telescopes will show some hint of the individual stars of which the brightest is of magnitude +14.

The total luminosity of M14 is in the order of 400,000 times that of the Sun corresponding to an absolute magnitude of -9.12. The shape of the cluster is decidedly elongated. M14 is about 100 light-years across.

Imaged by Debra Holton

M12 (also known as NGC 6218) is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier on May 30, 1764.

Located roughly 3° from the cluster M10, M12 is about 16,000 light-years distant and has a spatial diameter of ~75 light-years. The brightest stars of M12 are of 12th magnitude. It is rather loosely packed for a globular and M12 was once thought to be a tightly concentrated open cluster.

Images by Andrew Wilson

M10 (also known NGC 6254) is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier on May 29, 1764, it was described as a “Nebula without stars.”

M10 has an apparent diameter of some 20′, about 2/3 the apparent diameter of the moon, which translates to a spatial diameter of 83 light-years at its estimated distance of 14,300 light-years. Viewed through medium sized telescopes it appears about half that size (8′ to 9′), as its brighter core is only 35 light-years across. 

Images by Andrew Wilson

Messier 9 (also known NGC 6333) is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier in 1764.

M9 is one of the nearer globular clusters to the centre of the Milky Way Galaxy with a distance of around 5,500 light-years. Its distance from Earth is 25,800 light-years. The total luminosity of this cluster is around 120,000 times that of the Sun, the absolute magnitude being -8.04.

The brightest individual stars in M9 are of apparent magnitude 13.5, making them visible in moderately sized telescopes. There have been 13 variable stars found in M9.

Images by Andy Wilson