ZAP // Dall-E-2
New observations show that planets that form in protoplanetary disks can trigger the cascade formation of subsequent planets — a finding that supports the domino effect in the sequential formation of planetary systems.
New radio astronomical observations of a forming planetary system reveal that once the first planets emerge near a star, they may influence the surrounding materialguiding it to form additional planets further away.
In this process, each planet plays a role in creating the followingjust like falling dominoes that trigger each other.
Planets form in protoplanetary disks — massive clouds of gas and dust that surround young stars. So far, astronomers have identified more than 5,500 planetary systems, with more than 1,000 confirmed to have multiple planets.
Despite this knowledge, the exact process of development of multiplanetary systems like our Solar System remains to be clarifiedhighlights the .
Case study: PDS 70
A key system for studying planet formation is PDS 70, a young star located 367 light-years away in the constellation Centaurus.
It’s the only known star where fully formed planets have been directly observed within a protoplanetary disk using optical and infrared imaging.
A. Müller et al. / THAT
First confirmed image of a newborn planet in the PDS 70 system, captured by ESO’s VLT.
Previous radio wave observations from the Atacama Large Millimeter/submillimeter Array (ALMA) detected a ring of dust grains beyond the orbits of the two known PDS 70 planets.
However, these initial observations did not have the necessary resolution to explore the detailed structure of the ring.
In this investigation, an international team led by Kiyoaki Doia researcher at the Max Planck Institute for Astronomy, carried out high-resolution observations of the protoplanetary disk around this system.
The team used ALMA again, but conducted the observations at a longer wavelength — as longer wavelengths are better at penetrating the dust cloud of the protoplanetary disk.
The new observations, presented in a recently published in the journal The Astrophysical Journal Lettersclearly show a concentration of dust grains to the northwest (top right) in the ring outside the orbits of the two existing planets.
The location of this dust clump suggests that previously formed planets interact with the surrounding diskconcentrating dust grains in a narrow region at the outer limit of their orbits. It is thought that these clumped dust grains will grow to form a new planet.
This work shows observationally that the formation of planetary systems, such as the Solar System, can be explained by the sequential formation of planets from the inside out through repeating this process; like a line of falling dominoes, each one triggering the next.
