The European Space Agency (ESA) has presented the largest and most detailed image ever produced of the centre of the Milky Way, the so-called Galactic Bulge: an extremely bright region densely populated with stars. This extraordinary “photograph” opens up new possibilities for scientists, who will be able to confirm the possible existence of exoplanets in this region and measure their mass through the tiny variations in starlight over time.

The Euclid Space Telescope acquired this enormous image in around 26 hours. It is a mosaic made up of nine pointings of its visible-light camera, each covering a portion of the sky larger than the full Moon.

In this image, Euclid captured more than 60 million stars, together with nebulae and star clusters. This extremely populated region of our galaxy is an ideal environment for the search for exoplanets through microlensing.

The news from Euclid is extraordinary: mapping the Galactic Bulge with such precision opens up unique prospects,” commented Gabriele Cescutti, UniTS Professor of Stellar Astrophysics. “Although this specific observing campaign was designed to exploit microlensing and search for exoplanets, such a density of stellar data is also extremely valuable for our research lines at UniTS. In our Department of Physics, we have been working for years on chemical evolution and ‘galactic archaeology’. We use spectroscopic and chemical data from stars to reconstruct, through theoretical models, the early history, formation timescales and origin of the elements in the bulge and nucleus of the Milky Way. High-resolution mosaics, such as the one produced by Euclid, are fundamental to understanding the precise distribution and nature of these stellar populations.

The University of Trieste is responsible for the operations of the two scientific instruments at the heart of the Euclid mission: VIS (Visible Instrument) and NISP (Near Infrared Spectrometer Photometer). In detail, UniTS researchers hold responsibility and coordination roles in several Key Projects dedicated to the scientific exploitation of Data Release 1 (DR1), expected around mid-2027, which concerns the study of cosmology through the statistical properties of the distribution and evolution of galaxies. UniTS also contributes to the production of cosmological numerical simulations based on High Performance Computing methodologies.

Image credits: European Space Agency - ESA.