Science & Tech · Space · 6 hrs ago
Astronomers Find a Candidate for a Massive Starless Galaxy
Researchers at Swinburne University of Technology in Australia have identified AGC 322753 as a candidate dark galaxy.
It contains about 2 billion times the Sun’s mass in hydrogen, but astronomers have not seen stars in it.
The team found the hydrogen signal by comparing observations from radio surveys made with telescopes in Puerto Rico and China.
The object may be an almost-dark galaxy, with stars too faint to detect, rather than completely starless.
Its signal also suggests the gas cloud may be rotating, even though current models predict that dark galaxies should not rotate.
Most galaxy-formation models also suggest that a gas cloud this large should form at least some stars, so the object could help explain why star formation is suppressed in some galaxies.
Further observations are needed to establish what AGC 322753 is and how it formed.
Astronomers have identified AGC 322753 as a candidate for an unusually massive galaxy with few or no visible stars.
The object contains roughly 2 billion times the Sun’s mass in hydrogen, according to the researchers.
Radio observations suggest the gas cloud may be rotating, a feature that current models say dark galaxies should not have.
The researchers say the object may contain stars too faint to detect, rather than being completely starless.
If confirmed, AGC 322753 could help scientists investigate why some galaxies form stars while others remain dark.
- Who
- Researchers at Swinburne University of Technology in Australia identified the candidate.
- What
- AGC 322753 is a candidate for a massive galaxy with very few or no visible stars. It contains roughly 2 billion solar masses of hydrogen.
- When
- The findings were reported on 2026-11-09. The exact date of the observations is not stated.
- Where
- The object’s location is not stated. Its hydrogen was detected in radio survey observations from Arecibo Observatory in Puerto Rico and China’s Five-Hundred-Meter Aperture Spherical Radio Telescope.
- Why
- The researchers are investigating how a galaxy could contain so much hydrogen yet form few stars, and whether it may be rotating.
This story does not have two clearly opposing sides.
Arecibo Observatory and China’s Five-Hundred-Meter Aperture Spherical Radio Telescope detected a massive cloud of hydrogen in separate radio surveys.
Wired reported that Swinburne University of Technology researchers had identified AGC 322753 as a candidate dark galaxy and published their findings in the Monthly Notices of the Royal Astronomical Society.
- Candidate
- AGC 322753
- Hydrogen mass
- Roughly 2 billion times the Sun’s mass
- Researchers
- Swinburne University of Technology, Australia
- Radio surveys
- Arecibo Observatory and Five-Hundred-Meter Aperture Spherical Radio Telescope
- Estimated hydrogen-to-stellar mass
- At least 40 to 1
What people are saying
The theoretical models and the simulations show us that dark galaxies shouldn't rotate, so this is extremely interesting