NGC 6791: Three Stellar Ages Illustration

White Dwarf Stars in Open Cluster NGC 6791

In studying the dimmest burned-out stars in globular star cluster NGC 6791, NASA's Hubble Space Telescope has uncovered a paradox: three different populations of stars exist in an object where all the stars should have formed at the same time out of an interstellar cloud of gas...

NGC 6791: Digitized Sky Survey View

This is a ground-based telescopic view of NGC 6791, located 13,300 light-years away in the constellation Lyra.

NGC 6791: Full Hubble ACS Field

The full Hubble Advanced Camera for Surveys field is full of stars estimated to be 8 billion years old. Two background galaxies can be seen at upper left.

Small Region of ACS Field Reveals Faint White Dwarfs

A blow-up of view of a small region of the Advanced Camera for Surveys field reveals very faint white dwarfs. The hotter dwarfs are 4 billion years old and the cooler dwarfs are 6 billion years old.

Ground-Based Image Showing Location of NGC 6791

Zooming into an Open Star Cluster Yields Unexpected Results

This movie takes a closer loook at Hubble's image of NGC 6791, one of the oldest and largest open clusters known. The detection of white dwarfs that vary in age leads astronomers to rethink the theory that stars found in these clusters develop at the same time from large clouds...