Credit: ESA / Hubble & NASA, J. Kalirai
Several of the colored stars are grouped close together in this image of NGC 1805 globular cluster NGC 1805 NASA/ This Hubble Space Telescope. This tiny cluster of thousands of stars sits near the edge of the Large Magellanic Cloud, our own galaxy Milky Way. The stars orbit closely together, like bees swarming around a hive. In the dense center of one of these clusters, the stars are 100 to 1,000 times closer together than the closest stars to our sun, making the surrounding planetary systems unlikely.
The striking difference in star colors is beautifully illustrated in this image, which combines two different types of light: blue stars, the brightest in near-ultraviolet light, and red stars, illuminated in red and near-infrared. Space telescopes like Hubble can detect ultraviolet rays because they are positioned above the Earth’s atmosphere, which absorbs most of this wavelength, making it inaccessible to ground installations.
This young globular cluster can be seen from the Southern Hemisphere, in the constellation Dorado, and in Portuguese means dolphin fish. Globular clusters usually contain stars that are born at the same time. However, NGC 1805 is unusual in that it appears to host two different star constellations millions of years apart. Observing such clusters of stars can help astronomers understand how stars evolve, and the factors that determine whether they end their lives as white dwarves or explode as supernovae.
