Arthur Puls (CAMK, Warsaw)
Heavier elements (atomic number larger than ~30) are produced in stellar nucleosynthesis by neutron-capture, which is known to happen either by the r- (rapid) process and the s- (slow) process. In the context of Galactic Chemical Evolution, the elements in the third r-process peak (Os, Ir, Pt) are among the least studied species of the periodic table. This is due to observational challenges: the lines of these elements featuring in stellar spectra are weak, in crowded wavelengths, and appear in cool (FGK-type) stars, in which those (blue, near-UV) wavelengths have relatively low flux. In this talk, I will present the results of the first study focusing on a homogeneous set of stellar abundances for the third r-process peak, which more than doubled the availability of Os, Ir, Pt stellar abundances from high resolution spectra in the literature. The implications of the results for our understanding of the nature of the r-process, both in terms of physics and astrophysical sites, will also be discussed.
winter break
winter break
CAMK Annual Meeting
Tomasz Miller (Copernicus Center, Jagiellonian University, Cracow)
Simon Murphy (University of Southern Queensland, Australia)
The ages of stars are notoriously difficult to determine, especially for young stars that are still shrouded in dust or surrounded by discs. Here, every Myr matters, as we try to probe the processes of planet formation and stellar composition build-up. If stellar ages are biased, the knock-on effects for exoplanet characterisation are huge, affecting not just demographics, but even the detection probabilities for direct imaging searches. I discuss the various challenges in ascertaining the ages of hot, young stars, and how stellar population synthesis can help us assess whether common tools like stellar isochrones are leading us astray. I will present asteroseismology as an alternative technique capable of achieving better age precision, which approaches 10% for pre-main-sequence stars, before wrapping up with a few ideas on where this research can break new ground.
Arpita Misra (Jagiellonian University, Cracow)
Daniela Turis-Gallo (Universidad de Valparaiso, Chile)
Dominika Król (Harvard Smithonian CfA)
Maciek Wielgus (Instituto de Astrofísica de Andalucía, IAA-CSIC, Granada, Hiszpania)
