, Jeffries, RD ORCID: https://orcid.org/0000-0001-5668-1288, Jackson, RJ, Franciosini, E, Sacco, GG, Bayo, A, Magrini, L, Randich, S, Arancibia, J, Bergemann, M, Bragaglia, A, Gilmore, G, Gonneau, A, Hourihane, A, Jofré, P, Korn, AJ, Morbidelli, L, Prisinzano, L, Worley, CC and Zaggia, S (2021) The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232. Monthly Notices of the Royal Astronomical Society, 505 (1). pp. 1280-1292.

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2105.01153v1.pdf - Accepted Version

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stab1351.pdf - Published Version

Astrometry and photometry from {\it Gaia} and spectroscopic data from the {\it Gaia}-ESO Survey (GES) are used to identify the lithium depletion boundary (LDB) in the young cluster NGC 2232. A specialised spectral line analysis procedure was used to recover the signature of undepleted lithium in very low luminosity cluster members. An age of $38\pm 3$ Myr is inferred by comparing the LDB location in absolute colour-magnitude diagrams (CMDs) with the predictions of standard models. This is more than twice the age derived from fitting isochrones to low-mass stars in the CMD with the same models. Much closer agreement between LDB and CMD ages is obtained from models that incorporate magnetically suppressed convection or flux-blocking by dark, magnetic starspots. The best agreement is found at ages of $45-50$\,Myr for models with high levels of magnetic activity and starspot coverage fractions $>50$ per cent, although a uniformly high spot coverage does not match the CMD well across the full luminosity range considered.