Hubble image archive

Search for Red Dwarf Stars in Globular Cluster NGC 6397

[Left] – A NASA Hubble Space Telescope image of a small region (1.4 light-years across) in the globular star cluster NGC 6397. Simulated stars (diamonds) have been added to this view of the same region of the cluster to illustrate what astronomers would have expected to see if fa...

Date
Jan 1, 1994
Mission
Hubble Space Telescope
Archive ID
hubblesite-images-1994-41-198-image
By

[Left] – A NASA Hubble Space Telescope image of a small region (1.4 light-years across) in the globular star cluster NGC 6397. Simulated stars (diamonds) have been added to this view of the same region of the cluster to illustrate what astronomers would have expected to see if faint red dwarf stars were abundant in the Milky Way Galaxy. The field would then contain 500 stars, according to theoretical calculations.

[Right ] – The unmodified HST image shows far fewer stars than would be expected, according to popular theories of star formation. HST resolves about 200 stars. The stellar density is so low that HST can literally see right through the cluster and resolve far more distant background galaxies. From this observation, scientists have identified the surprising cutoff point below which nature apparently doesn't make many stars smaller that 1/5 the mass of our Sun. These HST findings provide new insights into star formation in our Galaxy.

Technical detail: The globular cluster NGC 6397, one of the nearest and densest agglomerations of stars, is located 7,200 light-years away in the southern constellation Ara. This visible-light picture was taken on March 3, 1994 with the Wide Field Planetary Camera 2, as part the HST parallel observing program.

Credits

F. Paresce, ST ScI & ESA and NASA

Image Details

About The Object
Object NameNGC 6397
R.A. Position17h 40m 41.35s
Dec. Position-53° 40' 25.29"

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Source

Image and source material are credited to the official mission archive linked below.

View on NASA.gov

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