Cool Stars 14 - Submitted Abstract # 107
This version created on 05 October 2006

Rotation Periods of Stars in NGC 2362:  Extending the Timeline for
Angular Momentum Evolution


Catrina M. Hamilton, Dickinson College
Kyle Bushong, UMass
Christopher M. Johns-Krull, Rice University

We present the results of a photometric monitoring program in the
young (3-5 Myr) open cluster NGC 2362.  Observations were carried out
using the automated 32-inch telescope at Tenagra Observatory over 108
nights between 3 December 2003 and 21 March 2004 (2 observations per
night).  Eighty-five images were obtained during this period through a
Cousins I-band filter.  A periodogram analysis of this data set has
detected 59 previously unknown periodic variables with a FAP < 1%.
The periodic variability of these stars presumably results from the
rotation modulation of starlight by stellar spots.  We compare the
period distribution seen to that of the younger clusters NGC 2264 (age
~ 3 Myr) and the Orion Nebular Cluster (ONC, age ~ 1 Myr) known from
the literature.  We find that the period distribution of NGC 2362 is
similar to that of the ONC and NGC 2264, but is shifted to shorter
periods.  These results will be discussed in the context of rotation
period evolution of young stars, consistent with conservation of
angular momentum and shrinking stellar radius.

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