Ancient variable stars, of a type known as RR Lyrae, have been discovered in the centre of the Milky Way for the first time. RR Lyrae stars typically reside in ancient stellar populations over 10 billion years old, such as globular clusters. These stars may even be the remains of the most massive and oldest surviving star cluster of the entire Milky Way.
Astronomers using the VISTA telescope at ESO’s Paranal Observatory have discovered a previously unknown component of the Milky Way. By mapping out the locations of a class of stars that vary in brightness called Cepheids, a disc of young stars buried behind thick dust clouds in the central bulge has been found.