Blue stragglers in globular cluster 47 Tucanae

A star's light yields clues about its identity which are not revealed in an image. That's why astronomers use spectrographs to decode the light. A spectrograph disperses light into its component colors, providing information on a star's rotation velocity, temperature, and surface gravity. The spectrum above compares a computer-generated spectrum of a blue straggler star with one from the observation of the blue straggler in 47 Tucanae, taken by the Hubble Space Telescope's Faint Object Spectrograph. The model spectrum predicts the shape and depth of a blue straggler's spectral lines. Based on this comparison, the Hubble telescope observation clearly matches the model.


R. Saffer (Villanova University) and NASA/ESA

About the Image

NASA press release
NASA caption
Release date:29 October 1997, 06:00
Size:800 x 569 px

About the Object

Name:47 Tucanae, NGC 104
Type:Milky Way : Star : Grouping : Cluster : Globular
Distance:15000 light years

Image Formats

Large JPEG
138.8 KB
Screensize JPEG
155.9 KB

Also see our

Accelerated by CDN77