NASA / ESA / STSCI / H.RICHER,UBC / SCIENCE PHOTO LIBRARY NASA / ESA / STSCI / H.RICHER,UBC / SCIENCE PHOTO LIBRARY
White dwarf stars. Comparison between ground-based (left) and Hubble Space Telescope images of the globular star cluster M4. The HST view shows several faint white dwarf stars (ringed), remnants of collapsed stars. The ground-based image shows the whole of M4, some 47 light years in diameter and about 7000 light years from Earth. The HST view is just 0.63 light years across, and shows the white dwarf stars among larger yellow sun-like stars and small red dwarf stars. The observations will be used to refine theories of the rate at which white dwarf stars cool and to help estimate the age of the Universe.
Model release not required. Property release not required.