ROTATION IN THE PLEIADES WITHK2. II. MULTIPERIOD STARS

Rotation periods for very low mass stars in the Pleiades

We present the results of a photometric monitoring campaign for very low mass (VLM) members of the Pleiades. Periodic photometric variability was detected for nine VLM stars with masses between 0.08 and 0.25 M⊙. These variations are most likely caused by co-rotating, magnetically induced spots. In comparison with solar-mass stars, the photometric amplitudes are very low (< 0.04mag), implying th...

New Bvic Photometry of Low-mass Pleiades Stars: Exploring the Effects of Rotation on Broadband Colors

We present new BVIC photometry for 350 Pleiades proper motion members with 9 < V ! 17. Importantly, our new catalog includes a large number of Kand early M-type stars, roughly doubling the number of low-mass stars with well-calibrated Johnson/Cousins photometry in this benchmark cluster. We combine our new photometry with existing photometry from the literature to define a purely empirical isoc...

On the lithium abundance dispersion in late-type Pleiades stars

I present the results of a programme to monitor the strengths of the Li I 6708Å, K I 7699Å and chromospheric Hα lines in a group of cool Pleiades stars. Consistent instrumentation and analysis techniques are used to show that there is no Li I variability on timescales of 1 year that could possibly account for the apparent spread in Li abundances seen in Pleiades stars between effective temperat...

X-ray Variability and Rotation in the Pleiades

Ca II activity and rotation in F-K evolved stars

Ca II H and K high resolution observations for 60 evolved stars in the field and in 5 open clusters are presented. From these spectra chromospheric fluxes are derived, and a homogeneous sample of more than 100 giants is built adding data from the literature. In addition, for most stars, rotational velocities were derived from CORAVEL observations. By comparing chromospheric emission in the clus...