Astronomers using the NASA/ESA Hubble Space Telescope NGC 2005A globular cluster located in the constellation Dorado, 162,000 light years from Earth.
This Hubble image shows the globular cluster NGC 2005. The color composite was created from images taken in visible and near-infrared light by Hubble's Wide Field Camera 3 (WFC3). It is based on data acquired through three filters. The colors are produced by assigning a different hue to each monochromatic image associated with an individual filter. Image credit: NASA / ESA / Hubble / F. Niederhofer / L. Girardi.
Globular clusters are dense systems of very old stars bound by gravity into a single structure about 100-200 light years in diameter.
Star clusters contain hundreds of thousands, or even millions, of stars. A large mass at the center of the cluster pulls the stars inward, forming a sphere of stars. sphericalThese clusters are named after the Latin word ” ,” which means “little sphere.”
Globular clusters are among the oldest known objects in the universe, relics of early galaxy formation.
Of the Milky Way's 150 globular clusters, about 70 are located within 13,000 light-years of the galactic center, where their density tends to peak.
“Studying globular clusters in space is a bit like studying fossils on Earth: just as fossils give us insight into the characteristics of ancient plants and animals, globular clusters reveal the signature of ancient stars,” the Hubble astronomers said.
“Current theories of galactic evolution predict that galaxies will merge with each other.”
“The relatively large galaxies observed in the modern universe are widely thought to have formed by the merger of smaller galaxies.”
“If this is correct, astronomers will see evidence that the oldest stars in nearby galaxies originated in different galactic environments.”
“Globular clusters are known to contain ancient stars, and their stability makes them excellent laboratories to test this hypothesis.”
“NGC 2005 is just such a globular cluster, and its very existence provides evidence in support of the theory of galactic evolution by mergers.”
NGC 2005 is located about 750 light-years from the center of the Large Magellanic Cloud, the Milky Way's largest satellite galaxy.
Also known as ESO 56-138, this globular cluster is discovered It was discovered on September 24, 1826 by Scottish astronomer James Dunlop.
“The stars in NGC 2005 have a different chemical composition than the stars in the surrounding Large Magellanic Cloud,” the researchers said.
“This suggests that the Large Magellanic Cloud merged with another galaxy at some point in its history.”
“While other galaxies have long ago merged or dispersed, NGC 2005 remains as an ancient witness to a long-ago merger.”
Source: www.sci.news
