NASA has released a picture of a “spherical cluster” containing thousands of bright stars. The Hubble Space Telescope used its Wide Field Camera 3 and Advanced Camera for Surveys to capture this image of the globular cluster NGC 6569 in the constellation Sagittarius.
Globular clusters are stable and tightly bound clusters containing tens of thousands to millions of stars. They are generally much larger than open clusters and are tightly bound by gravity. The strong gravitational attraction between closely packed stars gives them their regular spherical shape, hence the nomenclature “spheroid”.
They are generally populated with older, redder stars than are found in open clusters; Later red stars may disperse before becoming old. Gravitational attraction also makes them very stable allowing them to live for a very long time, living up to billions of years.
All types of star clusters are of great interest to astronomers because the constituent stars with similar internal compositions would have formed at roughly the same time and place. Therefore, these stellar clusters provide useful insight into how stars form and evolve. But observing individual stars within globular clusters is challenging because they are so densely packed.
This new image comes from the investigation of globular clusters that lie close to the center of our galaxy. Such objects were avoided in previous surveys because the dusty center of our galaxy blocks their light and changes the color of the stars within them. A star’s color is especially important to astronomers because it can give information about their age, composition and temperature.
The scientists who proposed these new observations combined data from Hubble with data from the Astronomical Archives, allowing them to measure the age of globular clusters such as NGC 6569. Their research also helped to give insight into the structure and density of globular clusters towards the center. Galaxy.