84 Hidden Hypersoft X-ray Sources Illuminate a Quiet Galactic Population
Astronomers using NASA's Chandra X-ray Observatory identified 84 faint, low-energy X-ray sources across six nearby galaxies (including Andromeda and M101). These hypersoft X-ray sources emit mainly extreme ultraviolet light and show little higher-energy X-ray emission, hinting at a population that could include accreting white dwarfs, neutron stars, or black holes. Some may be precursors to Type Ia supernovae, suggesting a much larger hidden population that could influence galactic environments. Confirming their nature will require simultaneous ultraviolet and X-ray observations, and the study—published in Nature Astronomy—indicates we may be only seeing the tip of a much larger iceberg.