A colorful, close-up view of the globular star cluster NGC 6362 has been taken by astronomers using the MPG/ESO 2.2-m telescope at ESO’s La Silla Observatory in Chile.
This image shows the globular cluster NGC 6362, a brilliant ball of ancient stars in the southern constellation of Ara (ESO)
Discovered in 1826 by the Scottish astronomer James Dunlop, the globular cluster NGC 6362 is located 24,800 light-years away in the southern constellation of Ara, and can be easily seen in a small telescope.
Globular star clusters are among the oldest objects in the Universe, and NGC 6362 cannot hide its age in this picture. The many yellowish stars in the cluster have already run through much of their lives and become red giant stars. But globular clusters are not static relics from the past – some curious stellar activities are still going on in these dense star cities.
NGC 6362 is home to many old stars that really do succeed in passing for a younger age. All of the stars in a globular cluster formed over a fairly short period of time, typically about 10 billion years ago for most globulars. Yet blue stragglers are bluer and more luminous than they should be after ten billion years of stellar evolution. Blue stars are hot and consume their fuel quickly, so if these stars had formed about ten billion years ago, then they should have fizzled out long ago.
Astronomers are keen to understand the secret of the youthful appearance of blue stragglers.
There are two possibilities: stars colliding and merging, and a transfer of material between two companion stars. The basic idea behind both of these options is that the stars were not born as big as we see them today, but that they received an injection of extra material at some point during their lifetimes and this then gave them a new lease of life.
