White Dwarf Stars in M4
A view of globular cluster M4 (fourth object in the Messier catalog of star clusters and nebulae). The nearest globular cluster to Earth (7,000 light-years away), and containing more than 100,000 stars, M4 was the target of a Hubble Space Telescope search for white dwarf stars.
The box (right of center) shows the small area that Hubble telescope probed.
Credit: M. Bolte (University of California, Santa Cruz) and Kitt Peak National Observatory 0.9-meter telescope
A Hubble Space Telescope color image of a small portion of the cluster only 0.63 light-years across reveals eight white dwarf stars (inside blue circles) among the cluster's much brighter population of yellow sun-like stars and cooler red dwarf stars.
Hubble reveals a total of 75 white dwarfs in one small area within M4, out of the total of about 40,000 white dwarfs that the cluster is predicted to contain.
Credit: Harvey Richer (University of British Columbia, Vancouver, Canada) and NASA