Szczegóły seminarium
Data: 14.05.2024
Elena Pancino (INAF, Arcetri)
StarDance: the non-canonical evolution of stars in cluster
Streszczenie:
Thanks to their ubiquity, brightness, and the fact that they are made of
stars with similar properties, star clusters have been used as
astrophysical laboratories or test particles in an impressive range of
research domains. However, we still do not understand fundamental
details of their formation and evolution. In spite of recent
technological progress, a list of unsolved problems and apparently
isolated mysteries has been accumulating over time, some standing since
decades. Among them, the existence of multiple stellar populations in
globular clusters, with different chemistry, has challenged generations
of researchers. They are not the result of classical galactic chemical
evolution, mostly mediated by supernovae, and they jeopardize the use of
clusters as simple stellar population templates for extragalactic
studies. Given the mounting problems faced by the most favored scenarios
to explain multiple populations, it is now time to revisit the
foundations of our current thinking. New results show that: (i) the
peculiarities in the chemistry of multiple populations are not limited
to the oldest globular clusters; (ii) they can be transient in the
evolution of individual cluster stars; and most importantly (iii) binary
interactions and fast stellar rotation cannot be neglected in the study
of star clusters and do have the capability to produce the observed
chemistry. The StarDance hypothesis assumes that multiple stellar
populations and five other non-canonical stellar populations (extreme
horizontal branch stars and hot sub-dwarfs; extended main sequence
turn-offs; red stragglers and sub-subgiants; lithium-rich stars; and
blue stragglers) are caused by the interplay between stellar rotation
and binary interactions, that are greatly enhanced in the special
environment of star cluster, with spectacular results.
Bio
Elena obtained her PhD in Padova. Postdocs at ESO then in Bologna, where she also was a member of Gaia DPAC group. Currently she is a professor at Arceti Observatory of INAF, near Florence. She leads the ERC Advanced Grant StarDance.