Poster
I. M. Rolo, E. Delgado Mena, M. Tsantaki, J. Gomes da Silva
Abstract
Much of what makes a star lithium rich is still a mystery. Magnetic activity, in particular the
phenomena usually associated with it, and the lithium abundance of stars are in general thought
to be connected. However as of today, it is unclear just how. In this work, in hopes of shedding
light on this conundrum, we study a sample of young but evolved intermediate mass red giants,
some of which are lithium rich, in open clusters where planets have been searched. We make
use of radial velocity and stellar activity signals to look for relations between the variations
observed and the surface lithium abundance of these stars. We find that the measurements of
dispersion of the stellar activity signals increase exponentially with the lithium abundance of the
stars in our sample. To strengthen our analysis we also look for correlations as well as periodic
temporal variations in stellar activity signals that may connect variability observed in radial
velocity to stellar activity. High correlations also tend to be found preferentially for stars with
higher lithium abundances. Interestingly, we also find that most of the lithium rich giants in our
sample either show strong correlations between radial velocity measurements and at least one
of the stellar activity indicators considered or reveal periodic variability in these signals. This
work thus provides evidence that red giants with higher lithium abundances are also more
magnetically active.
Cool Stars 22
San Diego, USA
2024 June
