High-resolution ALMA observations of the reflection nebula NGC 1333 revealed more than 400 ultra-thin, bow-shaped molecular rings around a jet from a young star in the SVS 13 system. The nested rings act as time-stamped records of repeated energetic outbursts, and the innermost ring matches a bright event observed in the early 1990s. Published in Nature Astronomy, the results provide the first direct observational confirmation that episodic accretion onto protostars drives sudden increases in jet activity.
ALMA Reveals 400+ Nested Rings Around a Newborn Star — Solving a 30-Year Star-Formation Mystery
Composite image of the star-forming region NGC 1333 obtained by combining data from the 8.2 m Subaru Telescope and the Digitized Sky Survey. | Credit: NAOJ, NOAO/AURA/NSF, Robert Gendler, Roberto Colombari
Go outside on a clear winter night and look southeast to see Orion's Belt and its bright companions. Just above that stellar grouping lies the quieter constellation Perseus, home to the Perseus Molecular Cloud and one of the nearest stellar nurseries to Earth: NGC 1333, nicknamed the Embryo Nebula. Though faint to the unaided eye, this reflection nebula teems with infant stars shaping and lighting the surrounding gas and dust.
High-Resolution ALMA Images Uncover a Star's Explosive Past
On Dec. 16, 2025, astronomers published the highest-resolution images to date of a fast-moving molecular jet launched by a newborn star in the binary system SVS 13. Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the team produced a detailed three-dimensional view that revealed more than 400 ultra-thin, bow-shaped molecular rings nested around the jet.
Rings as Time-Stamps
Each ring records the aftermath of a discrete energetic eruption — like tree rings that preserve a tree's history. The pattern of nested rings indicates the star has undergone repeated, powerful outbursts over decades. Crucially, the innermost ring corresponds to a bright outburst observed in the SVS 13 system in the early 1990s, giving researchers a rare direct link between a documented accretion event and a measurable change in jet speed.
An artist's impression of GRB 250702B, a bright white orb with rays of light coming out among a white and pink cloud surrounded by the blackness of space.
"These images give us a completely new way of reading a young star's history," said study co-author Gary Fuller, professor at the University of Manchester. "Each group of rings is effectively a time-stamp of a past eruption."
Why This Matters
The findings, reported in Nature Astronomy, provide the first direct observational confirmation of a long-standing theoretical model in star formation: protostars grow by episodic accretion of gas, and rapid increases in accretion drive bursts that amplify jet activity. Those bursts expel material at varying speeds, producing the quasi-periodic ring structures ALMA observed.
Because NGC 1333 lies only about 1,000 light-years away in Perseus, this discovery offers an unusually clear laboratory for studying how young stars gain mass and how their early eruptions influence the environment where planets may form.
For more striking imagery, see the Space Photo of the Week archives and the latest high-resolution data from observatories such as ALMA and the James Webb Space Telescope.
