Space Telescope

How did India's ASTROSAT space observatory contribute to our understanding of dwarf galaxy formation and evolution?

India's ASTROSAT made a groundbreaking discovery by observing the formation process of dwarf galaxies located 1.5 to 3.9 billion light years from Earth. Using its Ultraviolet Imaging Telescope, researchers captured 17 hours of data showing star-forming complexes on the outskirts of these galaxies and documented material moving inward from the outer edges toward the center of 11 dwarf galaxies. This observation provides crucial evidence for how dwarf galaxies, containing only a few billion stars, evolve into mature systems like the Milky Way with 200-400 billion stars. The study, published in Nature and led by astronomers from India, the US, and France, represents the first concrete documentation of this evolutionary process. The findings are significant because they address current gaps in theoretical models of galaxy evolution and demonstrate ASTROSAT's remarkable capabilities as a UV observatory for probing galaxy assembly processes.