Hubble Finds Young White Dwarfs on the Fast Track

These images show young and old white dwarf stars - the burned-out relics of normal stars - in the ancient globular star cluster NGC 6397.

The image at left, taken by a ground-based telescope, shows the dense swarm of hundreds of thousands of stars that make up the globular cluster. The white box outlines the location of the observations made by the NASA/ESA Hubble Space Telescope.

The image at top, right, taken by Hubble's Advanced Camera for Surveys, reveals young white dwarfs less than 800 million years old and older white dwarfs between 1.4 and 3.5 billion years old. The photo shows 12 of the 84 white dwarfs in the Hubble study. The blue squares pinpoint the young white dwarfs; the red circles outline the older white dwarfs. The Hubble researchers distinguished the younger from the older white dwarfs based on their colour and brightness. The younger white dwarfs are hotter and therefore bluer and brighter than the older ones.


Credit for Ground-based Image: D. Verschatse (Antilhue Observatory, Chile)
Credit for Hubble Images: NASA, ESA, and H. Richer (University of British Columbia)

About the Image

NASA press release
NASA caption
Release date:4 December 2007, 16:00
Size:3000 x 2400 px

About the Object

Name:NGC 6397
Type:Milky Way : Star : Grouping : Cluster : Globular
Distance:9000 light years
Category:Star Clusters

Image Formats

Large JPEG
1.8 MB
Screensize JPEG
463.3 KB

Colours & filters

606 nm Hubble Space Telescope
814 nm Hubble Space Telescope

Notes: The left image was captured by the ground-based Antilhue Observatory.

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