When our galaxy was born, around 13 billion years ago, a plethora of clusters containing millions of stars emerged. But over time, they have been disappearing. However, hidden behind younger stars that were formed later, some old and dying star clusters remain, such as the so-called E 3. European astronomers have now studied this testimony to the beginnings of our galaxy.
Globular clusters are spherical-shaped or globular stellar groupings — hence its name- which can contain millions of stars. There are about 200 of them in the Milky Way, but few are as intriguing to astronomers as the E 3 cluster.
It is situated around 30,000 light years away, in the southern constellation of Chameleon. A team of Spanish and Italian astronomers have named it “a ghost from the Milky Way’s past” in an article published recently in the Astronomy & Astrophysics journal.
“This globular cluster, and a few similar ones — such as Palomar 5 or Palomar 14 — are ‘ghosts’ because they appear to be in the last stages of their existence, and we say ‘from the past’ because they are very old. They were formed when our galaxy was virtually new-born, 13 billion years ago,” says one of the authors, Carlos de la Fuente Marcos.
E 3 is hidden behind younger and brighter objects located between the cluster and Earth, but it has been possible to analyse it thanks to the Very Large Telescope (VLT) held in the European Southern Observatory (ESO) in Cerro Paranal, Chile. The data obtained revealed…