Globular clusters

Globular clusters are spheroidal conglomerates containing hundreds of thousands of stars. Formed a few hundred million years after the Big Bang, they are among the oldest objects in the Galaxy. Our group studies these fascinating stellar systems to shed light on events in the primordial universe that led to the formation and evolution of globular clusters and their stars.

The main research lines on globular clusters include:

Multiple Stellar Populations in Globular Clusters
Most globular clusters host various populations of stars with distinct chemical compositions and kinematic properties. Some stars in globular clusters are similar to those found in the Galaxy, while others have characteristics not found anywhere else in the local Universe. The multiple populations in globular clusters provide clues to some of the major open questions in stellar astrophysics and cosmology, including the origin of globular clusters, their role in the formation of the Galaxy, and their contribution to the reionization of the Universe. Our group studies these topics using innovative techniques based on the synergy of spectroscopy, astrometry, and high-precision multi-band photometry obtained with ground-based instruments and major space telescopes (such as Hubble and James Webb).
Contacts: Antonino Milone

Binaries, Blue Stragglers, and Other Exotic Stars
Globular clusters can present extreme stellar densities, making them ideal environments for studying the formation and destruction of binary or multiple star systems and the merging of stars. Additionally, they host objects with extreme properties, such as cataclysmic variables, millisecond pulsars, stellar black holes, and even intermediate-mass black holes. Our group is active in studying binary stars and other 'exotic' objects within galactic star clusters and the Magellanic Clouds.
Contacts: Antonino Milone

Stellar Evolution
Our group uses star clusters as laboratories to study stellar evolution, particularly focusing on little-known evolutionary phases. These include the phenomenon of extended turn-offs and zigzag sequences in Magellanic Cloud clusters, UV-dim stars recently discovered by our group, or brown dwarf stars that our group has observed for the first time in globular clusters.
Contacts: Antonino Milone

Globular Clusters in the Galactic Bulge
These globular clusters form a category with substantial differences from the more well-known halo globular clusters. They not only contain the clusters with the highest metal content, but some of the metal-poor ones might be among the oldest in the galaxy. Our group studies their kinematics, ages, and the chemical peculiarities of the stars they contain.
Contacts: Sergio Ortolani

  Field Stars

Galactic Structure
The Gaia database is used in tandem with various spectroscopic surveys (Gaia-ESO, GALAH, LAMOST) to study the structure of the Galactic disk, its separation into thin and thick disks, and the dark matter content.
Contacts: Giovanni Carraro

  Local Group

Dynamics of Stellar Systems:
Analytical and numerical studies on the role of binary stars in the dynamics of star clusters and dwarf galaxies and in estimating the dynamic mass of these systems.
Contacts: Giovanni Carraro

  Open Clusters

Open Clusters:
These are low-mass systems located in the Galactic disk, whose true nature is not easy to discern. Various machine learning and AI algorithms are used to discriminate their true nature and build the most complete catalog possible to statistically study the properties of this family. Along with Gaia, the potential of the new 4MOST spectroscopic survey will be explored.
Contacts: Giovanni Carraro