Overview
- Two peer-reviewed studies published Oct. 9 in Nature Astronomy and MNRAS report a robust lensing detection in the system B1938+666.
- The object, roughly one million solar masses and nearly 10 billion light-years away, revealed itself as a tiny pinch in a radio Einstein ring.
- Researchers combined the GBT, VLBA and EVN into an Earth-sized interferometer, with data correlated at JIVE to resolve the subtle distortion.
- This is the lowest-mass detection by gravitational lensing to date, about 100 times below previous finds, demonstrating a new sensitivity regime.
- Its identity remains uncertain—either a dark-matter clump or an ultra-compact inactive dwarf galaxy—and teams are analyzing more data and surveying additional lenses to assess their abundance.