Overview
- Observations with the Very Large Telescope’s X-shooter instrument show gas moving at two distinct orbital velocities, which the authors interpret as two concentric gaseous rings separated by a clear gap.
- Spectroscopy detects rocky-planet elements such as calcium, oxygen, magnesium and iron, with the inner ring enriched in magnesium and the outer ring relatively depleted.
- The research team proposes that two planetesimals on separate orbits are maintaining and supplying gas to the rings, though those bodies are inferred indirectly rather than directly imaged.
- Based on dynamical estimates, the inner orbiting body could be a few kilometres across like a typical asteroid while the outer body could be as large as Pluto or the Moon.
- The findings, published in Nature Astronomy, present a new example of how planetary material can survive and reorganize after a star dies and motivate follow-up observations to test the planetesimal hypothesis and map the system’s dynamics.