Cool Stars 14 - Submitted Abstract # 86
This version created on 05 October 2006

The Monitor project:  Rotation periods of low-mass stars in young open
clusters


Jonathan Irwin, Institute of Astronomy (Cambridge)
Suzanne Aigrain, Institute of Astronomy (Cambridge)
Simon Hodgkin, Institute of Astronomy (Cambridge)
Jerome Bouvier, Laboratoire d'Astrophysique (Grenoble)
Cathie Clarke, Institute of Astronomy (Cambridge)
Leslie Hebb, University of St Andrews
Estelle Moraux, Laboratoire d'Astrophysique (Grenoble)

We have begun a high-cadence time-series photometric survey of young
open clusters and star forming regions, the Monitor project.  The
primary science goals are to look for low-mass eclipsing binary and
transiting planet systems, but a useful side-effect is the ability to
determine rotation periods for ~hundreds of low-mass cluster members.
We present results from three clusters:  NGC 2362 (~5 Myr), NGC 2516
(~150  Myr) and M34 (~200  Myr), covering stellar masses from ~0.2 to
1.0  M_sun.  We detect >100  new rotation periods in each cluster and
compare our results to existing measurements and models of angular
momentum evolution, finding in general that solid body models can
reproduce the evolution of the fast rotators, but core-envelope
decoupling may be required for the slow rotators, in agreement with
previous work.  By comparing our data in NGC 2362 to the extensive ONC
(~1 Myr) and NGC 2264 (~2 Myr) rotation period samples in the
literature, we intend to place additional constraints on disc locking
models (work in progress).  We also hope to present preliminary
results for other clusters currently under analysis, including the ONC
(where have detected 250  rotation periods, of which 100  are new
detections) and NGC 2547 (~30  Myr).  When complete, the survey will
give a relatively well-sampled age sequence from 1 to 200  Myr.

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