Seminars at FGG
Constraining the internal structure of Blue Straggler Stars with Asteroseismology
Speaker: Lorenzo Briganti (Universita' di Bologna (Italy))
Date and time: 2026-07-01 10:00
Blue straggler stars (BSSs) are core-hydrogen-burning stars resulting from dynamical processes such as accretion by mass transfer, mergers or collisions. Due to their origin, they are considered key objects in understanding the dynamics of their host clusters, and therefore their astrometric, photometric, and spectroscopic properties have been extensively studied for many decades. Recently, there has been growing interest in the internal structure of BSSs and in searching for clues about their dynamical past, leading to an encounter between these stars and asteroseismology. In this talk, I will present the first systematic analysis of old, low-mass, BSSs’ evolutionary models, both collisional and post-mass-transfer, in the 𝛾 Doradus instability region and show that their gravity-mode period-spacing patterns exhibit periodic modulations produced by chemical stratifications. These results highlight the potential of asteroseismology in constraining the origin of dynamical products and identifying them among field stars or within the main sequences of clusters (as is the case for blue lurkers). This will lead to the search for these signatures in data from existing space missions such as Kepler and TESS, as well as from future or candidate missions, such as PLATO or HAYDN. This synergy between asteroseismology and stellar clusters is fundamental to improving our knowledge of stellar physics.