Unveiling structures in the evolution of magnetic activity of solar-like stars

Mathur, Savita; Santos, Ângela R. G.; Claytor, Zachary R.; García, Rafael A.; Strugarek, Antoine; Finley, Adam; Noraz, Quentin; Amard, Louis; Beck, Paul G.; Bonanno, Alfio; Breton, Sylvain N.; Brun, Allan Sacha; Cao, Lyra; Corsaro, Enrico; Godoy-Rivera, Diego; Palakkatharappil, Dinil B.; Pinsonneault, Marc; van Saders, Jennifer
Bibliographical reference

8th TESS/15th Kepler Asteroseismic Science Consortium Workshop

Advertised on:
8
2024
Number of authors
18
IAC number of authors
3
Citations
0
Refereed citations
0
Description
The magnetic and rotational properties of solar-like stars are strongly coupled due to the interaction of rotation and convection in their outer envelopes, which fuels their magnetic dynamos and, as a consequence, their magnetic activity cycles. Thanks to the large number of Kepler targets with measured rotation periods and photometric magnetic activity index, S_ph, we investigate how magnetic activity evolves in solar-like stars. We compute the stellar Rossby number, Ro, the ratio between the rotation period and the convective overturn timescale, using the Yale Rotating Evolution Code. We divide our sample of main-sequence single stars by spectral type, revealing distinct patterns in their magnetic activity index relative to their Rossby number. In this talk, we will present the results of such analysis. Notably, G and K dwarfs exhibit a pronounced decline in S_ph around Ro/Ro_Sun of 0.3, indicative of a transitional phase that coincides with the location of the intermediate-rotation period gap. In contrast, F dwarfs, characterized by shallower convective zones, do not show any trend of S_ph versus Ro, particularly as the effective temperature rises. These deviations likely stem from the faster evolutionary pace of F dwarfs. Our analysis indicates that the Sun shares a comparable magnetic activity level with other Sun-like stars, selected so as to have similar effective temperature and metallicity. We will discuss our findings in the context of current dynamo models.