All stars are represented by spheres of the same radius, so different apparent sizes indicate different distances. The yellow stars that appear near the end are part of Eggren's moving group and are not thought to be part of the Hyades cluster. The green circle defines the tidal radius for the cluster, which is about 10 pc in diameter. This is the radius, inside of which, the stars are on average sufficiently close to each other to induce significant tidal effects.
The Hyades cluster contains approximately 200 stars and is about 50 parsecs from Earth. It lies on the face of the bull in the constellation Taurus, and seems to be about 500 million years old.
Usage: Use the "Play" button and "Stop" button to control rotation of the cluster. When stopped, "Back" steps back one step and "Step" steps forward one step. "Home" returns to the beginning from any point.