NGC 6528 is a

globular cluster A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Sagittarius, and is listed in the

New General Catalogue The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and ...

. It has an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

of about 11 and a diameter of about 16 arcminutes, and its Shapley-Sawyer Concentration Class is V, containing stars of 16th magnitude and dimmer. Dreyer described it as "pF, cS, R", meaning poor and faint, considerably small and round. NGC 6528 is located southwest of

NGC 6522 NGC 6522 is a globular cluster in the constellation Sagittarius. It is apparent magnitude 8.3, and diameter 16.4 arc minutes, and class VI with stars 16th magnitude and dimmer. It was discovered by William Herschel on June 24, 1784. It is cente ...

, another globular cluster. Both are located in

Baade's Window Baade's Window is an area of the sky with relatively low amounts of cosmic dust, interstellar dust along the line of sight from Earth. This area is considered an observational "window" as the normally obscured Galactic Center of the Milky Way is ...

, a relatively clear area near the galactic equator. The globular cluster was discovered in 1784 by the astronomer

William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline H ...

with his 18-inch

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

s. The NGC 6528 is unusually metal-rich for a globular cluster, and is very similar in composition to NGC 6553, suggesting an origin in a similar environment. N6522 32ins

References

Robert Burnham, Jr Robert Burnham Jr. (June 16, 1931 – March 20, 1993) was an American astronomer, best known for writing the classic three-volume ''Burnham's Celestial Handbook''. He is the discoverer of numerous asteroids including the Mars crossing asteroid 3 ...

, ''Burnham's Celestial Handbook: An observer's guide to the universe beyond the solar system'', vol 3, p. 1555
NGC 6528 @ SEDS

External links

* Globular clusters Sagittarius (constellation) 6528 {{star-cluster-stub