LOW-MASS STARS IN THE CENTRAL REGION OF THE HYADES CLUSTER

New V and I photometry of Hyades candidates is presented and used to improve the determination of the low-mass stellar population of the central 5 degrees X5 degrees region of the cluster. We use color-magnitude diagrams appropriate for the metallicity of the cluster to identify likely members from proper motion and photometric surveys, and to identify possible unresolved Hyades binaries. The resulting candidate sample consists of 49 objects (38 apparently single stars plus 11 probable unresolved binaries) with 0.4 greater than or equal to, mass/M.greater than or equal to 0.1 which have both proper motions and colors consistent with cluster membership, plus 13 faint (19 less than or equal to V less than or equal to 22.5) objects around the hydrogen-burning limit which lack proper motions but which have colors consistent with membership. We present new H alpha observations which further support the contention that Hyades members less massive than about 0.3M. all have H alpha in emission, in agreement with the expectation of longer spindown time scales for lower mass stars. A cluster luminosity function based on 63 individual stars is presented. Comparison with theoretical models indicates that the present cluster mass function is flat at these low masses, implying that brown dwarfs make up no more than similar to 10% of the total mass of the cluster.