New Observations Reveal Clues to Giant Planet Formation
Astronomers have made new observations of a young star that could provide insights into the formation of giant planets like Jupiter. Using the Very Large Telescope and the Atacama Large Millimeter/submillimeter Array, scientists have detected clumps in the dense material surrounding a star known as V960 Mon, which have the potential to collapse under gravity and form the seeds of massive planets.
The discovery is significant as it marks the first-ever detection of such clumps around a young star that could give rise to gas giant planets, according to astronomer Alice Zurlo of the Universidad Diego Portales in Chile.
Gas giant planets, like Jupiter, are believed to form through two possible pathways. The first is core accretion, where clumps of material accumulate to grow into a planet, similar to the way rocky planets like Earth and Mars form. The second pathway is gravitational instability, where a denser clump in a dense cloud collapses under gravity to form a baby planet, mirroring the process of star formation.
To better understand these formation routes, astronomers have been studying the material around young stars for signs that shed light on the early stages of planet formation. Advancements in technology and analysis techniques have made it easier to detect subtle variations in the distant dusty material.
V960 Mon, located approximately 7,120 light-years away in the Monoceros constellation, is a young star that recently experienced a flare event. Observations of the star taken using the VLT’s optical and near-infrared SPHERE instrument, two years after a 2014 outburst that saw the star flare to 20 times its previous brightness, revealed peculiar structures resembling spiral arms in the surrounding material. This prompted a team of scientists led by astronomer Philipp Weber of the University of Santiago, Chile, to examine radio data from ALMA.
The ALMA data unveiled the fragmentation of the disk of material around V960 Mon, a crucial aspect of the gravitational instability model. The disk fragments into clumps that collapse into the seeds of planets. Remarkably, the team detected clumps in the spiral arms around V960 Mon, each with several times the mass of Earth.
“This is the first observation of gravitational instability happening at planetary scales. No one had ever seen it before,” says Weber.
Scientists now plan to conduct further studies using current and upcoming telescopes to investigate other young stars that have experienced outbursts, in hopes of finding additional evidence of disk fragmentation and gravitational instability during planet formation.
“For over a decade, we’ve been searching for these clumps with ALMA, as theories of planet formation predict their presence in the creation of large planets,” explains astronomer Sebastián Pérez of the University of Santiago, Chile.
The findings have been published in The Astrophysical Journal Letters. This discovery could potentially establish a direct link between the formation of stars and planets, offering new insights into the early stages of planetary systems.