NASA's Hubble Space Telescope has captured an image of a large collection of aging stars that scientists think could be as ancient as 10 billion years old.
An image released by NASA on June 29 shows a massive globular cluster of a gravitationally bound collection of stars orbiting the Milky Way. The image of the star cluster is a composite of separate exposure acquired by Hubble's Wide-Field Camera 3 instrument.
"This rich and dense smattering of stars is a massive globular cluster, a gravitationally bound collection of stars that orbits the Milky Way," NASA described the image.
Globular clusters are denser and more spherical compared with open star clusters such as the famous Pleiades. Large galaxies including the Milky Way host globular clusters. Astronomers think that there are between 150 and 180 of these star clusters orbiting the Milky Way.
NGC 6139, the particular globular cluster captured by Hubble, is one of the globular clusters orbiting our galaxy.
Globular clusters, which typically contain hundreds of thousands of stars believed to have formed at about the same time, are robust. While the universe and the galaxies evolved over time, many of these globular clusters remained intact for billions of years.
Most of those that orbit the Milky Way is estimated to be more than 10 billion years old, which means that they contain some of the oldest stars in the galaxy, having formed very early in the Milky Way's history.
Globular clusters are thus helpful in estimating the age of the universe and the center of a galaxy. It also helps shed light on other objects and phenomena in the universe.
A study published in the Monthly Notices of the Royal Astronomical Society in June proposed that idea that supermassive stars may have been born around the same time their host global clusters started to form.
The NGC 6139, which lies about 35,000 light-years away, was first discovered in May 1826 by Scottish astronomer James Dunlop.
The stellar cluster is seen roughly in the direction of the Milky Way's center, in the constellation of Scorpius. The constellation serves as astronomers' goldmine for finding interesting astronomical objects, such as the Butterfly Nebula, binary star systems, and other star clusters.