A global partnership involving U-M scientists has utilized JWST to unveil an unparalleled view into the genesis of planets around nascent stellar systems

Researchers from the University of Michigan have participated in a global collaboration that offers an unmatched glimpse into the birth of planets utilizing the JWST—the most potent space telescope ever deployed.

Specifically, the team focused on PDS 70, a youthful star hosting two developing planets in its orbit. Situated 370 light-years away, this system presents scientists with a rare opportunity to observe the formation and development of planets during their nascent stages.

This recent investigation, headed by Dori Blakely, a doctoral candidate at the University of Victoria, along with an international cohort of researchers, employed an inventive methodology using JWST’s distinct instruments to uncover intricate details regarding the planets and the swirling disk of gas and dust in which they are forming.

“Our objective with JWST is to validate concepts regarding these protoplanets that have been theorized by other observatories,” stated Michael Meyer, a co-author of the research and chair of the U-M Department of Astronomy. “These observations differentiate the light emanating from the protoplanet and the light from the circumstellar disk surrounding it, utilizing this unique capacity.”

The outcomes, published in The Astronomical Journal, present a new outlook on how planets develop over time while vying with their host stars for resources.

A youthful star and its planetary formation site

PDS 70 is a young star, only about 5 million years old—essentially a newborn compared to our sun, which is 4.6 billion years old. Encircling this young star is a disk of gas and dust, flattened like a pancake, with a significant void in the center where the two planets, PDS 70 b and PDS 70 c, are being formed.

This void serves as a construction zone for planets, where fresh worlds are gathering materials to enlarge.

“We’re capturing moments of the initial phases of planetary development, revealing what occurs as planets strive for survival in their cosmic nursery,” remarked Blakely. “What’s astonishing is that we can observe not just the planets themselves, but the very process of their creation—they’re contending with their star and each other for the gas and dust they require to expand.”

To achieve such a clear view of the planets and disk, the team utilized JWST’s Near-Infrared Imager and Slitless Spectrograph, or NIRISS, in its aperture masking interferometry mode—a savvy technique involving the telescope. They placed a specialized mask with several minuscule holes over the telescope, allowing only a limited amount—roughly 15%—of the light to pass through and interfere, generating overlapping patterns, akin to the way ripples from two pebbles interact on water’s surface.

Through examining these patterns, they could ‘visualize’ the concealed intricacies of the system with remarkable accuracy.

“This inventive approach is akin to dimming the young star’s dazzling spotlight, enabling the observation of the details around it—in this instance, planets,” stated René Doyon, director of the Trottier Institute for Research on Exoplanets, or IREx. Doyon is also the principal investigator for JWST’s NIRISS instrument.

This methodology allowed the team to reveal characteristics that traditional telescope imaging cannot detect, establishing this study as a pioneering proof of concept for such observations with the powerful space telescope. With its ability to discern details at an unprecedented level, JWST is transforming the way we investigate planets and their origins.

“This research demonstrates how JWST is capable of accomplishing something entirely novel,” expressed Loïc Albert, JWST NIRISS instrument scientist at IREx. “We’re employing groundbreaking techniques to examine planets in manners we’ve never attempted before.”

U-M’s Meyer, who has contributed to the development of JWST instruments for many years, is thrilled that astronomers are getting a demonstration of the new potentials offered by NIRISS.

“This marks the beginning of a longer narrative,” Meyer stated. “This isn’t the conventional method of gathering data that most scientists are accustomed to, but it holds immense power. We aspire to apply it to various systems, and we encourage others to utilize it.”

Former U-M graduate student Matthew De Furio, along with former U-M postdoctoral researchers Gabriele Cugno and Alexander Greenbaum, are co-authors of the research.

Planetary giants still in development

The JWST observations validated the existence of two massive planets still in their developmental stages. These planets are absorbing material from the disk, much like children collecting building blocks to build a tower.

The researchers assessed the planets’ light in the mid-infrared spectrum using JWST’s NIRISS instrument and concluded that both planets seem to be gathering gas—a crucial phase in their evolution. The robust detection signatures of PDS 70 b and PDS 70 c enabled accurate measurements of their brightness and positions.

These findings provide direct proof that the planets are still in a growth phase, contending with their host star for resources in the disk, supporting the notion that planets form through a process of ‘accretion,’ gradually accumulating mass from the surrounding gas and dust.

This rare glimpse of planets during their growth phase may assist scientists in comprehending how worlds similar to Jupiter and Saturn formed within our own solar system.

“These observations present us with an exceptional opportunity to observe planet formation as it unfolds,” stated Doug Johnstone, principal research officer at the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Center.

“Observing planets in the act of accreting materials aids in addressing long-standing questions about the formation and evolution of planetary systems. It’s akin to witnessing a solar system being constructed right before our eyes.”

The data also implies that the planets may possess rings of material surrounding them, known as circumplanetary disks. These disks could be regions where moons are forming—similar to those orbiting Jupiter and Saturn today.

A Progression in Planetary Science

The discoveries regarding PDS 70 provide astronomers with an enhanced understanding of how planets and stars coalesce and develop in tandem. By observing these planets grow and interact within their environment, scientists gain insights into how planetary systems—like our own—come into existence.

“This is akin to viewing a family portrait of our solar system in its infancy,” remarked Blakely. “It’s remarkable to consider how much knowledge we can extract from this single system.”

One of the most captivating discoveries was the identification of a faint, unresolved light source within the gap of the protoplanetary disk. While the nature of this emission remains unclear, it could signify a formation such as a spiral arm composed of gas and dust, or even a third planet developing within the system.

Further observations utilizing JWST’s other instruments will be essential to confirm whether this glow indicates a new planet, a feature of the disk, or something entirely unforeseen.

This research is part of the NIRISS Guaranteed Time Observations program, overseen by Johnstone.