2019/05/16 by S. T. Douglas, J. L. Curtis, M. A. Agüeros +4 · 3 citations
Physics and Astronomy · #Angular momentum #Astro and Planetary Science #Astrometry #Cluster (spacecraft) #Open cluster #Photometry (optics) #Pulsars and Gravitational Waves Research #Rotation (mathematics) #Star cluster #Stars #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/ab2468
Accepted for publication in ApJ. 20 pages, 10 figures, 5 tables. CSV versions of tables 2, 3, and 4 available by request
arxiv created 2019/05/16 · openalex created_date 2019/05/29 · openalex publication_date 2019/07/10 · arxiv updated 2019/07/17 · openalex updated_date 2026/08/06
Abstract We analyze K2 light curves for 132 low-mass (1 M ⊙ ≳ M * ≳ 0.1 M ⊙ ) members of the 600–800 Myr old Hyades cluster and measure rotation periods ( ) for 116 of these stars. These include 93 stars with no prior measurements; the total number of Hyads with a known is now 232. We then combine literature binary data with Gaia DR2 photometry and astrometry to select single-star sequences in the Hyades and its roughly coeval Praesepe open cluster and derive a new reddening value of A V = 0.035 ± 0.011 for Praesepe. Comparing the effective temperature– distributions for the Hyades and Praesepe, we find that solar-type Hyads rotate, on average, 0.4 day slower than their Praesepe counterparts. This difference indicates that the Hyades is slightly older than Praesepe: we apply a new gyrochronology model tuned with Praesepe and the Sun and find an age difference between the two clusters of 57 Myr. However, this difference decreases and eventually disappears for lower-mass stars. This provides further evidence for stalling in the rotational evolution of these stars and highlights the need for more detailed analysis of angular momentum evolution for stars of different masses and ages.