Bernhard Aringer (Uppsala University): The new carbon stars

Thursday 6 Feb 2025, 14:00 → 15:00 Europe/Stockholm

101132Å

Title: The new carbon stars
Speaker: Bernhard Aringer
Affiliation: Uppsala University
Time: Thursday 6 February 2025, 1400 to 1500
Location: 101132Å

Zoom: if requested 

Abstract:

Carbon stars are characterized by a carbon to oxygen ratio above one, which is usually caused by internal nuclear and convective processes or mass transfer in binaries.  Especially the objects situated on the Asymptotic Giant Branch are important producers of chemical elements (carbon, s-process elements) and dust.  They contribute significantly to the infrared luminosity of galaxies and have recently been used as distance indicators. Their cool atmospheres are dominated by the opacities of dust and billions of molecular transitions. In this seminar talk I will discuss the newest line data for important species like C2, CN, HCN, C2H2 or C3 and their impact on synthetic atmospheric structures and stellar spectra. It will be shown, how they improve the ability of our models to reproduce the observed spectra and colours of carbon stars. An additional topic are the limitations of current models and possible improvements.