Li-rotation connection in pre-Main Sequence, solar and low-mass stars

A connection between lithium depletion and rotation has been reported for a handful of stellar clusters/associations spanning ages from ~5 to ~150 Myrs. This relation can give us insights about transport processes in stellar interiors, hidden from observations otherwise. For this reason, it is imperative to expand the knowledge of the lithium-rotation connection to more clusters (checking its universality), and to better understand its evolution and the different factors at play, like environment and formation scenario.
To test the environmental effects we check the case of the stellar stream Pisces-Eridanus, wich is similar in age to the Pleiades. Combing rotational periods (Prot) from the literature with our own high resolution, optical spectroscopic observation with FEROS, we found that the Li-rotation relation was comparable with the one in the Pleiades, which tells us that this relation might be independent of the formation environment.
To test the evolution of the Li-Rotation relation, we analyzed two cases, the Upper Scorpius association (USco) and the TW Hydrae moving group (TWA). Both stellar groups have ages close to ~10 Myr, which is an ideal young age to trace the origins of the lithium-rotation relation, but old enough to study "clean samples", since most of their members have lost their discs, and the ones that still preserved them are not supposed to be (dynamicaly) locked by them anymore.
In the case of TWA, we collected and analyzed TESS light-curves from which we obtained rotational periods (Prot) from spot modulation, assessed possible contamination given the large pixel scale, and complemented this information with Lithium equivalent width (EWLi) values from the literature. Although we have a small sample, we found that there is a significant spread in EWLi in the temperature range ~3500-4500 K. Moreover, there is a hint that the Li-Prot connection is already operating in this population.
In the case of USco, we collected Prots from Rebull et al. 2018 (based on K2 data) and mined the literature for EWLi measurements. We will show preliminary results for this population that seems to be more complex to analyze. Since multiplicity can impact both, the determined Prot as well as the EWLi, for both populations we thoroughly addressed the multiplicity of their members taking advantage of different Gaia astrometric and photometric diagnostics, multiplicity catalogs and other indicators.