 The cluster is sufficiently close to the Sun that its distance can be directly measured by observing the amount of parallax shift of the member stars as the Earth orbits the Sun.This measurement has been performed with great accuracy using the Hipparcos satellite and the "Hubble Space Telescope".An alternative method of computing the distance is to fit the cluster members to a standardized infrared color–magnitude diagram for stars of their type, and use the resulting data to infer their intrinsic brightness.