WASHINGTON, September 12 (RIA Novosti) – A team of international scientists has used NASA's Hubble space telescope to discover the largest known group of dense bunches of stars called globular clusters, more than two billion light years away, the US space agency said Thursday.
A globular star cluster contains hundreds of thousands of stars and the population of around 160,000 globular star clusters – more than 1,000 times more than the 150 clusters in the Milky Way galaxy -- was spotted in the core of the grouping of galaxies known as Abell 1689, NASA said.
Peering deep inside the heart of Abell 1689, Hubble detected the visible-light glow of 10,000 globular clusters, some as dim as one-billionth the faintness of the dimmest star that can be seen with the naked eye.
Based on that number, the team of scientists estimated that more than 160,000 globular clusters are huddled within a diameter of 2.4 million light-years.
The clusters contain some of the oldest surviving stars in the universe.
"Even though we are looking deep into the cluster, we're only seeing the brightest globular clusters, and only near the center of Abell 1689 where Hubble was pointed," John Blakeslee of the National Research Council Canada's Herzberg Institute of Astrophysics said in a statement.
The star clusters discovered by Hubble are also the most distant ever studied, at 2.25 billion light-years away, NASA said.
The study was published this week in the online edition of the Astrophysical Journal.
