James Webb Telescope Unveils Role of Massive Stars in Planet Formation

James Webb Telescope Unveils Role of Massive Stars in Planet Formation
by Erica Marchand
Paris, France (SPX) Mar 01, 2024

Recent observations from the James Webb Space Telescope (JWST) have shed new light on the complex interplay between massive stars and the formation of planetary systems, offering groundbreaking insights into a long-standing astronomical puzzle. This revelation, stemming from an international collaboration involving CNRS scientists, focuses on a protoplanetary disc within the Orion Nebula, named d203-506, and its susceptibility to ultraviolet radiation from nearby massive stars.

Planetary systems, including our own Solar System, are thought to form from protoplanetary disks of dust and gas that orbit young stars. These disks provide the essential materials from which planets are born. However, the presence and influence of massive stars-those approximately 10 times the mass of the Sun and a staggering 100,000 times more luminous-play a pivotal role in determining the fate of these nascent planetary systems.

The study, poised to feature on the front page of the journal Science on March 1st, 2024, indicates that the intense ultraviolet (UV) radiation emitted by these colossal stars can either foster planet formation or prevent it entirely by dispersing the disk's material. In the case of the Orion Nebula's d203-506, the research suggests that the conditions are so harsh that the formation of Jupiter-like gas giants is virtually impossible due to the rapid dispersal of the disk's mass.

Building on these findings, another research paper delves deeper into the mechanisms at play, highlighting the first directly observed evidence of far-ultraviolet (FUV) driven photoevaporation-a process where the disk's upper layers are heated to the point that gas is expelled, leading to mass loss. This phenomenon is particularly detrimental to the formation of gas giant planets, as it strips away the disk's gas before these planets can fully form.

The study utilized both near-infrared and submillimeter measurements from JWST and the Atacama Large Millimeter Array to observe d203-506. Through detailed modeling of the disk's kinematics and the excitation of emission lines within photodissociation regions (PDRs), areas heavily influenced by UV photons from massive stars, it was determined that d203-506 is losing mass at a significant rate. This mass loss, driven by FUV heating and ionization, suggests that the disk could be devoid of gas within a million years, severely limiting the potential for gas giant formation within the system.

These discoveries underscore the critical role of massive stars in shaping the environments in which planetary systems develop. The research also provides a compelling example of how our own Solar System, believed to have formed in a cluster containing one or more massive stars, might have been influenced by similar processes of FUV radiation.

By elucidating the dynamics of protoplanetary disks and the formidable impact of stellar radiation, these studies offer valuable perspectives on the formation of planetary systems. They not only advance our understanding of the universe's complexity but also pave the way for future explorations into the mysteries of star and planet formation.

Research Report:A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk