Poster - Splinter Education   (SFG 0140 / virtual Edu)

What is the natural activity spread for same-age, same-mass cool stars?

D Dsouza(1), N Ilic (1), K Poppenhaeger(1)
(1) Leibniz-Institut für Astrophysik Potsdam (AIP)

Stellar magnetic activity decreases as stars spin down. However, it is still an open question how deterministic this spin-down is in quantitative terms; populations of stars with similar ages can display quite some scatter in their rotation and activity levels. In this master thesis project, I study wide binary stars of the same spectral type and find the scatter in activity between the binary pairs. I look at co-eval F, G, K and M spectral type binaries located in the solar neighborhood, identified from recently identified co-moving binaries from Gaia data. We use archival X-ray data from Chandra and XMM-Newton as an indicator of stellar activity. We have analyzed ca. 30 wide binary systems in X-rays, the majority of them being of spectral type K or M. Our preliminary results show that the activity scatter within the same-age, same-mass binary pairs is significantly smaller than the observed scatter of same-mass stars in the solar neighborhood. Our future analysis will provide a way to characterize the intrinsic scatter in the age-activity relationship for cool stars. In particular, we plan to investigate M dwarf pairs further, as their spin-down and activity decrease is of particular interest for habitable-zone exoplanets.