Overview
- The object, about 14 million light-years away by M94, was first flagged by China's FAST radio telescope and later mapped by the Green Bank Telescope and the Very Large Array before Hubble ruled out any starlight.
- Cloud-9 spans roughly 4,900 light-years, contains about one million solar masses of neutral hydrogen, shows no rotation, and appears bound by an inferred dark-matter halo of around five billion solar masses.
- Researchers classify it as the first confirmed Reionization-Limited H I Cloud, a long-predicted relic that retained gas after the epoch of reionization but never formed stars.
- The finding offers empirical support for models in which many low-mass dark-matter halos remain starless, providing a benchmark for galaxy-formation thresholds and potential dark-matter constraints.
- Independent experts urge caution until deeper follow-up fully excludes ultra-faint stars, and the team plans targeted searches as Cloud-9 could either gain mass and form stars or lose gas near M94 and dissipate.