The Age and Age Spread of the Praesepe and Hyades Clusters: a Consistent, ~800 Myr Picture from Rotating Stellar Models

Brandt, Timothy D. and Huang, Chelsea X. ORCID: (2015) The Age and Age Spread of the Praesepe and Hyades Clusters: a Consistent, ~800 Myr Picture from Rotating Stellar Models. The Astrophysical Journal, 807 (1):24. pp. 1-6. ISSN 1538-4357

Text (Published Version)

Download (552kB) | Preview


We fit the upper main sequence of the Praesepe and Hyades open clusters using stellar models with and without rotation. When neglecting rotation, we find that no single isochrone can fit the entire upper main sequence at the clusters' spectroscopic metallicity: more massive stars appear, at high significance, to be younger than less massive stars. This discrepancy is consistent with earlier studies, but vanishes when including stellar rotation. The entire upper main sequence of both clusters is very well-fit by a distribution of 800 Myr old stars with the spectroscopically measured [Fe/H] = 0.12. The increase over the consensus age of ∼600-650 Myr is due both to the revised solar metallicity (from Z⊙ ≈ 0.02 to Z⊙ ≈ 0.014) and to the lengthening of main-sequence lifetimes and increase in luminosities with rapid rotation. Our results show that rotation can remove the need for large age spreads in intermediate-age clusters, and that these clusters may be significantly older than is commonly accepted. A Hyades/Praesepe age of ∼800 Myr would also require a recalibration of rotation/activity age indicators.

Statistics for USQ ePrint 47435
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version deposited in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 31 Mar 2022 01:14
Last Modified: 31 Mar 2022 01:14
Uncontrolled Keywords: galaxies: clusters: individual (Hyades, Praesepe); Hertzsprung-Russell and C-M diagrams; methods: statistical; stars: early-type; stars: evolution; Astrophysics - Solar and Stellar Astrophysics
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Identification Number or DOI:

Actions (login required)

View Item Archive Repository Staff Only