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Seeds of Moons Scattered Among Protoplanets in the Centaurus Constellation

Astronomers observed ripe conditions for potential moon formation in a young solar system.

(CN) — In the nursery of a young star where two newborn planets continue to grow, research published in the Astrophysical Journal Letters on Thursday describes observations of conditions ripe for the birth of new moons.

"Our work presents a clear detection of a disk in which satellites could be forming," Myriam Benisty, a researcher at the University of Grenoble and the University of Chile, said in a statement. Benisty led the research using the Atacama Large Millimetre/submillimetre Array, also known as ALMA, in northern Chile.

"Our ALMA observations were obtained at such exquisite resolution that we could clearly identify that the disk is associated with the planet and we are able to constrain its size for the first time,” Benisty added.

Nearly 400 light years from Earth, the young star dubbed PDS 70 among the Centaurus constellation is an estimated 5.4 million years old. That dates the star's birth to Earth's Pliocene era.

A Jupiter-like protoplanet orbiting the star, PDS 70c, is surrounded by a ring-like formation called a circumplanetary disc, a structure that is instrumental in the formation of planets and their moons.

Researchers found no evidence of a circumplanetary disc associated with nearby PDS 70b, photos of which were first published in 2018.

"We used the millimeter emission from cool dust grains to estimate how much mass is in the disk and therefore, the potential reservoir for forming a satellite system around PDS 70c," said Sean Andrews, a study co-author and astronomer at the Center for Astrophysics in a statement.

Unstable particles of dust flow from the ring around the planet, forming tiny satellites smaller than a third of an inch. Through pebble- ccretion, the small grains can stick to each other and into grow larger satellites. Whether these will snowball into actual moons waits to be seen.

Though researchers are unsure of what materials the dust is made out of, they have observed complex structures in PDS 70c’s disc.

“Recent surveys revealed that almost ubiquitously, protoplanetary disks appear highly structured with rings and gaps, spiral arms and asymmetries. While other scenarios are discussed, these features are often interpreted as resulting from the presence of planets embedded in disks,” researchers explained in the paper.

The international team includes astronomers from the Harvard & Smithsonian Center for Astrophysics in Cambridge Massachusetts as well as researchers from Chile, France, the U.S., Germany, and the Netherlands.

In order to understand more about the budding solar systems, the scientists will continue to conduct chemical surveys and molecular line infrared observations.

“Upcoming studies of the gas kinematics and chemistry of PDS 70 will complement the view provided by this work, serving as a benchmark for models of satellite formation, planet-disk interactions and delivery of chemically enriched material to planetary atmospheres,” researchers said in the paper.

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