Formation of giant planets PDS 70 c and SR 12 c mirrors our solar system

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

The young planetary systems PDS 70 and SR 12 provide new insights into how giant planets and their moons form. By studying the dust disks surrounding the planets PDS 70 c and SR 12 c, it is clear that these distant worlds share significant similarities with the development of Jupiter and Saturn. These observations help explain how gas and dust accumulate to form planets and smaller satellites in the early stages of a star system's life.

The planets within the PDS 70 system grow within a shared gap in the disk of material surrounding the star. As these massive planets orbit, they exert forces that deplete the available gas and dust, limiting the material available for building smaller moons. This process is similar to how the early solar system functioned, where planetary growth and moon formation were linked through the interaction of gas and solid particles.

Measurements of PDS 70 c show that the dust disk contains a small but detectable amount of material at a temperature of 26 Kelvin. The physical scale of this disk supports theories where gas flows into the planet's gravitational territory, known as the Hill sphere. These findings align with established models of satellite formation, where the time required to form moons like Callisto or Iapetus fits within the 5.4 million-year age of the PDS 70 system.

Key findings
- PDS 70 c and SR 12 c are currently the only known planetary-mass objects with confirmed cold dust disks detected at submillimeter wavelengths.
- The PDS 70 system acts as a natural laboratory that parallels the formation history of Jupiter and Saturn.
- Dust mass estimates for PDS 70 c range from 0.007 to 0.031 Earth masses.
- Satellite formation timescales in these systems are consistent with models of gas-drag clearing of debris, taking between 1 and 10 million years.

Scientific study

PDS 70 c and SR 12 c: Observational Constraints on Giant-Planet and Satellite Formation (external link)