Webb opens new chapter in search for forming planets

Webb opens new chapter in search for forming planets
by Clarence Oxford
Los Angeles CA (SPX) Mar 28, 2024

In a pioneering effort to uncover the mysteries of planet formation, astronomers have directed the James Webb Space Telescope's (JWST) advanced capabilities toward protoplanetary disks, the birthplaces of planets. This initiative marks a significant milestone in the study of these nascent celestial bodies and their environments. Spearheaded by researchers from the University of Michigan, University of Arizona, and University of Victoria, this collaborative study integrates new JWST observations with previous data from the Hubble Space Telescope and the Atacama Large Millimeter Array (ALMA) to explore the disks surrounding protostars HL Tau, SAO 206462, and MWC 758.

The teams' findings, detailed in a series of papers published in The Astronomical Journal, reveal intricate interactions between the disks and the gas and dust envelopes encasing the central young stars. Notably, the University of Michigan's investigation into the SAO 206462 disk, led by astronomer Gabriele Cugno, unveiled a potential planet in formation, challenging prior expectations of planet characteristics. "Our observations suggest the planet could be colder or obscured, differing from the anticipated massive, hot, and bright body," Cugno explains, highlighting the unpredictable nature of planet formation.

Astronomical observations have historically depicted protoplanetary disks as sites of complex dynamics, often showcasing spirals and gaps indicative of planet formation. Yet, detecting these forming planets proves immensely challenging due to their faintness compared to their host stars. The JWST's NIRCam, equipped to capture infrared light, offers a new lens through which to study these elusive subjects, employing angular differential imaging to isolate the faint signals of potential planets from the overwhelming brightness of their stars.

Further insights from the University of Victoria and University of Arizona expand on the role of protostellar envelopes and spiral arms in disk structure and planet formation processes. Despite the absence of new planet detections in the MWC 758 disk, the research places stringent constraints on the presence of planets within these systems, suggesting that any responsible for observed disk features are likely low mass, low temperature, or obscured by dust.

This comprehensive survey underscores the significance of ongoing planet formation research, not only for understanding the genesis of gas giants but also for elucidating the mechanisms that govern the distribution of chemical elements within planetary systems. "Understanding how gas giant planets influence their protoplanetary disks is crucial for piecing together the puzzle of planet formation and evolution," notes Michael Meyer, a co-author from the University of Michigan.

The endeavor to observe forming planets continues, with the promise of JWST's unparalleled sensitivity bringing us closer to unraveling the intricacies of planetary system development.

JWST/NIRCam Imaging of Young Stellar Objects. I. Constraints on Planets Exterior to the Spiral Disk Around MWC 758

JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462

JWST/NIRCam Imaging of Young Stellar Objects III. Detailed Imaging of the Nebular Environment Around the HL Tau Disk