protoplanetary disks Archives

December 31, 2024December 31, 2024 by Matt Williams

A Young Exoplanet's Atmosphere Doesn't Match its Birthplace

The natal disk of PDS 70 with new planet PDS 70b (bright spot on the right). Credit: ESO/A. Müller et al.

If the modern age of astronomy could be summarized in a few words, it would probably be “the age of shifting paradigms.” Thanks to next-generation telescopes, instruments, and machine learning, astronomers are conducting deeper investigations into cosmological mysteries, making discoveries, and shattering preconceived notions. This includes how systems of planets form around new stars, which scientists have traditionally explained using the Nebular Hypothesis. This theory states that star systems form from clouds of gas and dust (nebulae) that experience gravitational collapse, creating a new star.

The remaining gas and dust then settle into a protoplanetary disk around the new star, which gradually coalesces to create planets. Naturally, astronomers theorize that the composition of the planets would match that of the disk itself. However, when examining a still-developing exoplanet in a distant star system, a team of astronomers uncovered a mismatch between the gases in the planet’s atmosphere and those within the disk. These findings indicate that the relationship between a protoplanetary disk and the planets they form might be more complicated.

December 25, 2024December 25, 2024 by Matt Williams

Webb Observes Protoplanetary Disks that Contradict Models of Planet Formation

Image of the star cluster NGC 346, captured by Webb's Near-Infrared Camera (NIRCam). Credit: NASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA)

The James Webb Space Telescope (JWST) was specifically intended to address some of the greatest unresolved questions in cosmology. These include all of the major questions scientists have been pondering since the Hubble Space Telescope (HST) took its deepest views of the Universe: the Hubble Tension, how the first stars and galaxies came together, how planetary systems formed, and when the first black holes appeared. In particular, Hubble spotted something very interesting in 2003 when observing a star almost as old as the Universe itself.

Orbiting this ancient star was a massive planet whose very existence contradicted accepted models of planet formation since stars in the early Universe did not have time to produce enough heavy elements for planets to form. Thanks to recent observations by the JWST, an international team of scientists announced that they may have solved this conundrum. By observing stars in the Small Magellanic Cloud (LMC), which lacks large amounts of heavy elements, they found stars with planet-forming disks that are longer-lived than those seen around young stars in our Milky Way galaxy.

October 7, 2024October 7, 2024 by Matt Williams

The JWST Reveals New Things About How Planetary Systems Form

This artist’s impression of a planet-forming disk surrounding a young star shows a swirling “pancake” of hot gas and dust from which planets form. Credit and ©: National Astronomical Observatory of Japan (NAOJ)

Every second in the Universe, more than 3,000 new stars form as clouds of dust and gas undergo gravitational collapse. Afterward, the remaining dust and gas settle into a swirling disk that feeds the star’s growth and eventually accretes to form planets – otherwise known as a protoplanetary disk. While this model, known as the Nebular Hypothesis, is the most widely accepted theory, the exact processes that give rise to stars and planetary systems are not yet fully understood. Shedding light on these processes is one of the many objectives of the James Webb Space Telescope (JWST).

In a recent study, an international team of astronomers led by University of Arizona researchers and supported by scientists from the Max Planck Institute of Astronomy (MPIA) used the JWST’s advanced infrared optics to examine protoplanetary disks around new stars. These observations provided the most detailed insights into the gas flows that sculpt and shape protoplanetary disks over time. They also confirm what scientists have theorized for a long time and offer clues about what our Solar System looked like roughly 4.6 billion years ago.

August 5, 2024August 5, 2024 by Mark Thompson

Astronomers See Planets Forming Around Binary Stars

Artist's illustration of binary star planet formation. Credit: S. Dagnello, NSF/AUI/NRAO

Over 5,000 exoplanets have been discovered around distant star systems. Protoplanetary disks have been discovered too and it’s these, out of which all planetary systems form. Such disks have recently been found in two binary star systems. The stellar components in one have a separation of 14 astronomical units (the average distance between the Earth and Sun is one astronomical unit) and the other system has a separation of 22 astronomical units. Studying systems like these allow us to see how the stars of a binary system interact and how they can distort protoplanetary disks.

May 23, 2024May 23, 2024 by Evan Gough

Astronomers Propose a 14-Meter Infrared Space Telescope

An artist's illustration of the SALTUS Observatory concept. SALTUS is a Far-IR space telescope that will open a new window into the cosmos. Image Credit: NASA

The Universe wants us to understand its origins. Every second of every day, it sends us a multitude of signals, each one a clue to a different aspect of the cosmos. But the Universe is the original Trickster, and its multitude of signals is an almost unrecognizable cacophony of light, warped, shifted, and stretched during its long journey through the expanding Universe.

May 22, 2024May 22, 2024 by Matt Williams

This is the Largest Planet-Forming Disk Ever Seen

The center of this composite image shows IRAS 23077, likely the largest planet-forming disk ever seen, which looks like a giant cosmic butterfly. Credit: Radio: SAO/ASIAA/SMA/K. Monsch et al; Optical: Pan-STARRS

Roughly 1,000 light-years from Earth, there is a cosmic structure known as IRAS 23077+6707 (IRAS 23077) that resembles a giant butterfly. Ciprian T. Berghea, an astronomer with the U.S. Naval Observatory, originally observed the structure in 2016 using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). To the surprise of many, the structure has remained unchanged for years, leading some to question what IRAS 2307 could be.

Recently, two international teams of astronomers made follow-up observations using the Submillimeter Array at the Smithsonian Astrophysical Observatory (SAO) in Hawaii to better understand IRAS 2307. In a series of papers describing their findings, the teams revealed that IRAS 23077 is actually a young star surrounded by a massive protoplanetary debris disk, the largest ever observed. This discovery offers new insight into planet formation and the environments where this takes place.

April 29, 2024April 29, 2024 by Evan Gough

JWST Uses “Interferometry Mode” to Reveal Two Protoplanets Around a Young Star

Astronomers used the JWST's interferometry mode to study the PDS 70 extrasolar system. Image Credit: Blakely et al. 2024.

The JWST is flexing its muscles with its interferometry mode. Researchers used it to study a well-known extrasolar system called PDS 70. The goal? To test the interferometry mode and see how it performs when observing a complex target.

March 28, 2024March 28, 2024 by Evan Gough

Webb Joins the Hunt for Protoplanets

This artist’s impression shows the formation of a gas giant planet embedded in the disk of dust and gas in the ring of dust around a young star. A University of Michigan study aimed the James Webb Space Telescope at a protoplanetary disk surrounding a protostar called SAO 206462, hoping to find a gas giant planet in the act of forming. Image credit: ESO/L. Calçada

We can’t understand what we can’t clearly see. That fact plagues scientists who study how planets form. Planet formation happens inside a thick, obscuring disk of gas and dust. But when it comes to seeing through that dust to where nascent planets begin to take shape, astronomers have a powerful new tool: the James Webb Space Telescope.

March 18, 2024March 21, 2024 by Matt Williams

Webb Finds Hints of a Third Planet at PDS 70

An artist's illustration of the PDS 70 system, not to scale. The two planets are clearing a gap in the circumstellar disk as they form. As they accrete in-falling material, the heat makes them glow. Image Credit: W. M. Keck Observatory/Adam Makarenko

The exoplanet census now stands at 5,599 confirmed discoveries in 4,163 star systems, with another 10,157 candidates awaiting confirmation. So far, the vast majority of these have been detected using indirect methods, including Transit Photometry (74.4%) and Radial Velocity measurements (19.4%). Only nineteen (or 1.2%) were detected via Direct Imaging, a method where light emitted or reflected from an exoplanet’s atmosphere or surface is used to detect and characterize it. Thanks to the latest generation of high-contrast and high-angular resolution instruments, this is starting to change.

This includes the James Webb Space Telescope and its sophisticated mirrors and advanced infrared imaging suite. Using data obtained by Webb‘s Near-Infrared Camera (NIRCam), astronomers within the MIRI mid-INfrared Disk Survey (MINDS) survey recently studied a very young variable star (PDS 70) about 370 light-years away with two confirmed protoplanets. After examining the system and its extended protoplanetary disk, they found evidence of a third possible protoplanet orbiting the star. These observations could help advance our understanding of planetary systems that are still in the process of formation.

March 4, 2024March 4, 2024 by Evan Gough

Massive Stars Have the Power to Shape Solar Systems

This image is a Hubble image of the inner regions in the Orion Nebula, with a JWST image of a protoplanetary disk named d203-506. The disk is close enough to the massive Trapezium Cluster stars that their UV radiation is shaping the planet-forming process in the disk. Image Credit: NASA/STSCI/RICE UNIV./C.O'DELL ET AL / O. BERNÉ, I. SCHROTTER, PDRS4ALL

Stars shape their solar systems. It’s true of ours, and it’s true of others. But for some massive stars, their power to shape still-forming systems is fateful and final.