The main-sequence rotation-colour relation in the Coma Berenices open cluster

Abstract

We present the results of a photometric survey of rotation rates in the Coma Berenices (Melotte 111) open cluster, using data obtained as part of the SuperWASP exoplanetary transit-search programme. The goal of the Coma survey was to measure precise rotation periods for main-sequence F, G and K dwarfs in this intermediate-age (~600 Myr) cluster, and to determine the extent to which magnetic braking has caused the stellar spin periods to converge. We find a tight, almost linear relationship between rotation period and J-K colour with a root-mean square scatter of only 2 percent. The relation is similar to that seen among F, G and K stars in the Hyades. Such strong convergence can only be explained if angular momentum is not at present being transferred from a reservoir in the deep stellar interiors to the surface layers. We conclude that the coupling timescale for angular momentum transport from a rapidly-spinning radiative core to the outer convective zone must be substantially shorter than the cluster age, and that from the age of Coma onward, stars rotate effectively as solid bodies. The existence of a tight relationship between stellar mass and rotation period at a given age supports the use of stellar rotation period as an age indicator in F, G and K stars of Hyades age and older. We demonstrate that individual stellar ages can be determined within the Coma population with an internal precision of order 9 percent (RMS), using a standard magnetic braking law in which rotation period increases with the square root of stellar age. We find that a slight modification to the magnetic-braking power law, P proportional to t^0.56, yields rotational and asteroseismological ages in good agreement for the Sun and other stars of solar age for which p-mode studies and photometric rotation periods have been published.

14 pages, 10 figures, accepted for publication in MNRAS

References in corpus (8)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• A fast hybrid algorithm for exoplanetary transit searches
• Deep MMT Transit Survey of the Open Cluster M37 III: Stellar Rotation at 550 Myr
• The Monitor project: Rotation of low-mass stars in the open cluster M34
• Analysis of 70 Ophiuchi AB including seismic constraints
• The first rotation periods in Praesepe
• RACE-OC Project: Rotation and variability in the open cluster NGC2099 (M37)

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