A revised age greater than 50 Myr for the young cluster IC 4665

Jeffries, Robin D; Jackson, Richard J; Binks, A S

Abstract

IC 4665 is one of only a dozen young open clusters with a “lithium depletion boundary” (LDB) age. Using an astrometrically and spectroscopically filtered sample of cluster members, we show that both the positions of its low mass stars in Gaia absolute colour-magnitude diagrams and the lithium depletion seen among its K- and early M-stars are discordant with the reported LDB age of $32^{+4}_{-5}$ Myr. Re-analysis of archival spectra suggests that the LDB of IC 4665 has not been detected and that the published LDB age should be interpreted as a lower limit. Empirical comparisons with similar datasets from other young clusters with better-established LDB ages indicate that IC 4665 is bracketed in age by the clusters IC 2602 and IC 2391 at 55 ± 3 Myr.

Citation

Jeffries, R. D., Jackson, R. J., & Binks, A. S. (2023). A revised age greater than 50 Myr for the young cluster IC 4665. Monthly Notices of the Royal Astronomical Society, 526(1), 1260-1267. https://doi.org/10.1093/mnras/stad2845

• Journal Article Type: Article
• Acceptance Date: Sep 13, 2023
• Online Publication Date: Sep 18, 2023
• Publication Date: 2023-11
• Deposit Date: Oct 3, 2023
• Publicly Available Date: Oct 3, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 526
• Issue: 1
• Pages: 1260-1267
• DOI: https://doi.org/10.1093/mnras/stad2845
• Keywords: Space and Planetary Science, Astronomy and Astrophysics