« back to overview Cluster Load higher resolution (1800 x 1200 Pixel    3500 x 2300 Pixel)
Object description
The star Antares, Messier 4 and NGC 6144 in the constellation of Scorpion

Object description:

Antares, the major star in the constellation Scorpio, illuminates the surrounding gas and dust masses and produces a rare yellow-orange reflection nebula. Along the line of sight, but far behind Antares, are two globular clusters, M 4 and NGC 6144.

Messier 4 (NGC 6121) is a globular cluster of concentration class IX (weak concentration). At a distance of only 7000 light-years, M4 is the closest globular cluster to the solar system and correspondingly well studied.

It has a physical diameter of 75 light-years and contains about 100 000 stars. A special study of more than 600 white dwarf stars suggests an age of about 12.7 billion years. First observed by Swiss astronomer Jean-Philippe Loys de Chéseaux in 1746, Messier 4 was described by Charles Messier in 1764 as "a cluster of very small stars, which with smaller telescopes appears more like a nebula".

NGC 6144 is a small globular cluster of concentration class XI. It is located just under 28 000 light years from the solar system. NGC 6144 was first observed by William Herschel on May 22, 1784. John Dreyer, a Danish-Irish astronomer, described it "as of considerable size, strongly concentrated, brightening toward the center, and readily resolvable into single stars."

Johan Ludvig Emil Dreyer created the NGC catalog, a list of more than 7000 star clusters, nebulae and galaxies and later as a supplement the IC catalog.

Information and images of the star Antares can be found here.

« Click here or the thumbnail to load a large annoted image and a size comparison to the full moon.

Sun Moon Solar System DeepSky Widefield Miscellaneous Spec. Projects
All Images and all Content are © by Franz Hofmann + Wolfgang Paech