Alex Binks
Rob Jeffries
Richard Jackson
2021-02-25
<p>We identify a lithium depletion boundary (LDB) in the open cluster NGC2232, using spectroscopy obtained for high-probability<br>
cluster members observed in the Gaia ESO Surveya. Using 2 “flavours” of evolutionary models: ones that adopt standard stellar physics (SMs) and models that incorporate some form of radius inflation either using starspots or large surface magnetic fields (MMs), we find that:<br>
<strong>(1) LDB ages from SMs strongly agree (38±2 Myr), and those from MMs are 10–20% older, where spot-covering fraction (fsp) scales with age.<br>
(2) The isochronal ages are 2-3 times younger using the SMs, and get closer to a 1:1 agreement for heavily-spotted models.</strong></p>
<p>These results show that ages determined from CMD fits are highly sensitive to the choice of model inputs, radius inflation plays a key role for young low-mass stars, and that additional “ingredients” for models are vital to provide a full, quantitative predictive theory of pre-MS evolution.</p>
To be presented at the Cool Stars 20.5 virtual conference.
https://doi.org/10.5281/zenodo.4563147
oai:zenodo.org:4563147
eng
Zenodo
https://zenodo.org/communities/coolstars20half
https://doi.org/10.5281/zenodo.4563146
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
open clusters
stars: pre-main sequence
lithium depletion boundary
A Lithium Depletion Boundary age of 40-50 Myr in NGC2232: Implications for tests of pre-main sequence stellar evolution
info:eu-repo/semantics/conferencePoster