A team led by Dante Minniti (Universidad Andrés Bello, Santiago de Chile) and Rodrigo Contreras Ramos (Instituto Milenio de Astrofísica, Santiago de Chile) used observations from the VISTA ( Visible and Infrared Survey Telescope ) infrared survey telescope, as part of the project of ESO over the Milky Way to carefully search the central part of the galaxy.
Thus, by observing infrared light, less affected by cosmic dust than visible light, and the fantastic conditions at ESO’s Paranal Observatory, scientists have been able to obtain the clearest view of the heart of the Milky Way ever. . And they discovered a dozen ancient RR Lyrae stars in the center of the previously unknown Milky Way.
The discovery of these stars, a type of object characterized by undergoing cyclical variations in brightness and size and that serve as a guide to measure distance in space (they are variable stars of the constellation Lyra), may offer us new information about the origin of this ancient area of the cosmos.
“The discovery of the RR Lyrae stars in the center of the Milky Way has important implications for the formation of the galactic nucleus. It supports the existence of a scenario in which the galactic bulge was formed from the merger of a few globular clusters ”, explains Rodrigo Contreras, co-author of the study.
The fact that the RR Lyrae stars are part of globular clusters then supports the theory that the heart of the Milky Way was not formed at the time by a rapid accretion of gas but by the accumulation of globular clusters.
The study has been published in The Astrophysical Journal Letters.
