Stars Identified in the Center of NGC 6397

Four types of stars reside within the center of the globular cluster NGC 6397. They have been identified in the accompanying image as: 1) helium white dwarfs; 2) blue stragglers; 3) normal white dwarfs; and 4) cataclysmic variables.

1) Helium white dwarfs (blue squares): Three faint blue stars that do not vary in brightness can be seen near the center of the cluster. These stars may be very-low-mass white dwarfs, formed in the cores of giant stars whose evolution is somehow interrupted by a stellar collision or an interaction with a binary companion. When a giant star interacts with another star, it can lose its outer layers prematurely, exposing its hot, blue core.

Credit:

NASA/ESA, A. Cool (SFSU) and Z. Levay (STScI)

About the Image

NASA press release
NASA caption
Id:opo0321b
Type:Observation
Release date:7 August 2003, 15:00
Size:600 x 600 px

About the Object

Name:NGC 6397
Type:• Milky Way : Star : Grouping : Cluster : Globular
• X - Star Clusters Images/Videos
Distance:9000 light years

Colours & filters

BandWavelengthTelescope
Ultraviolet
U
336 nm Hubble Space Telescope
WFPC2
Optical
B
439 nm Hubble Space Telescope
WFPC2
Infrared
I
814 nm Hubble Space Telescope
WFPC2

Image Formats

Large JPEG
142.5 KB
Screensize JPEG
337.2 KB

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