Observations of PDS 70 reveal new dust clumps and potential third planet

Star system: PDS 70 | Distance from the Sun: 370 light years

The young star PDS 70 is known to host two confirmed protoplanets within its disk of gas and dust. Recent observations have identified two elongated dust features near the star, which may indicate the presence of a previously unknown third planet or complex structures within the inner disk. These features share the same orbit, with one leading the other by approximately 120 degrees, suggesting they could be dust trapped by the gravity of an unseen planet.

Researchers utilized the SPHERE instrument to perform polarimetric and multi-band imaging, which captures scattered light from dust particles. Additionally, they employed the GRAVITY instrument to search for direct planetary signals. These methods allowed for the consistent detection of two distinct inner dust emissions and a marginal 3-sigma signal consistent with a planet about three times the mass of Jupiter.

The findings show that the detected dust clumps possess different colors, potentially pointing to variations in the size of the dust grains involved. The alignment of these features with a shadow in the outer disk provides further clues about the environment. While the data supports the idea of co-orbital dust—material trailing or leading a planet in its orbit—an alternative theory suggests these clumps might simply be rotating patterns within the inner disk itself.

Key findings
- Two elongated dust emissions detected in the inner region of the PDS 70 system.
- A marginal detection of a potential planet approximately three times the mass of Jupiter.
- Dust clumps are positioned 120 degrees apart on the same orbit, resembling co-orbital material.
- Variations in dust clump color suggest differences in grain sizes.
- The features may represent either an undetected planet or substructures within the inner disk.

Scientific study

Two inner dust clumps in PDS 70. A third protoplanet traced by trojan material or a substructured inner disk? (external link)