jwst Archives

April 15, 2024April 15, 2024 by Matt Williams

You Can't Know the True Size of an Exoplanet Without Knowing its Star's Magnetic Field

Artist's impression of a "hot Jupiter" orbiting close to a Sun-like star. Credit: NASA

In 2011, astronomers with the Wide Angle Search for Planets (WASP) consortium detected a gas giant orbiting very close to a Sun-like (G-type) star about 700 light-years away. This planet is known as WASP-39b (aka. “Bocaprins”), one of many “hot Jupiters” discovered in recent decades that orbits its star at a distance of less than 5% the distance between the Earth and the Sun (0.05 AU). In 2022, shortly after the James Webb Space Telescope (JWST) it became the first exoplanet to have carbon dioxide and sulfur dioxide detected in its atmosphere.

Alas, researchers have not constrained all of WASP-39b’s crucial details (particularly its size) based on the planet’s light curves, as observed by Webb. which is holding up more precise data analyses. In a new study led by the Max Planck Institute for Solar System Research (MPS), an international team has shown a way to overcome this obstacle. They argue that considering a parent star’s magnetic field, the true size of an exoplanet in orbit can be determined. These findings are likely to significantly impact the rapidly expanding field of exoplanet study and characterization.

April 12, 2024April 12, 2024 by Evan Gough

The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star

This artist's visualization of GRB 221009A shows the narrow relativistic jets (emerging from a central black hole) that gave rise to the gamma-ray burst (GRB) and the expanding remains of the original star ejected via the supernova explosion. Credit: Aaron M. Geller / Northwestern / CIERA / IT Research Computing and Data Services

After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst (GRB) struck the sensors on the Neil Gehrels Swift Observatory and the Fermi Gamma-Ray Space Telescope on October 9th, 2022. The GRB lasted seven minutes but was visible for much longer. Even amateur astronomers spotted the powerful burst in visible frequencies.

It was so powerful that it affected Earth’s atmosphere, a remarkable feat for something more than two billion light-years away. It’s the brightest GRB ever observed, and since then, astrophysicists have searched for its source.

April 5, 2024April 5, 2024 by Matt Williams

Webb Sees a Galaxy Awash in Star Formation

Starburst galaxy M82 was observed by the Hubble Space Telescope in 2006, which showed the galaxy’s edge-on spiral disk, shredded clouds, and hot hydrogen gas. The James Webb Space Telescope has observed M82’s core, capturing in unprecedented detail the structure of the galactic wind and characterizing individual stars and star clusters. Credit: NASA/ESA/CSA/STScI/Alberto Bolatto (UMD)

Since it began operations in July 2022, the James Webb Space Telescope (JWST) has fulfilled many scientific objectives. In addition to probing the depths of the Universe in search of galaxies that formed shortly after the Big Bang, it has also provided the clearest and most detailed images of nearby galaxies. In the process, Webb has provided new insight into the processes through which galaxies form and evolve over billions of years. This includes galaxies like Messier 82 (M82), a “starburst galaxy” located about 12 million light-years away in the constellation Ursa Major.

Also known as the “Cigar Galaxy” because of its distinctive shape, M82 is a rather compact galaxy with a very high star formation rate. Roughly five times that of the Milky Way, this is why the core region of M82 is over 100 times as bright as the Milky Way’s. Combined with the gas and dust that naturally obscures visible light, this makes examining M82’s core region difficult. Using the extreme sensitivity of Webb‘s Near-Infrared Camera (NIRCam), a team led by the University of Maryland observed the central region of this starburst galaxy to examine the physical conditions that give rise to new stars.

April 3, 2024April 3, 2024 by Andy Tomaswick

Could We Directly Observe Volcanoes on an Exoplanet?

After a few decades of simply finding exoplanets, humanity is starting to be able to do something more – peer into their atmospheres. The James Webb Space Telescope (JWST) has already started looking at the atmospheres of some larger exoplanets around brighter stars. But in many cases, scientists are still developing models that both explain what the planet’s atmosphere is made of and match the data. A new study from researchers at UC Riverside, NASA’s Goddard Spaceflight Center, American University, and the University of Maryland looks at what one particular atmospheric process might look like on an exoplanet – volcanism.

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 26, 2024March 26, 2024 by Evan Gough

In a Distant Solar System, the JWST Sees the End of Planet Formation

This artist's illustration shows what gas leaving a planet-forming disk might look like around the T Tauri star T. Cha. Image Credit: ESO/M. Kornmesser CC BY

Every time a star forms, it represents an explosion of possibilities. Not for the star itself; its fate is governed by its mass. The possibilities it signifies are in the planets that form around it. Will some be rocky? Will they be in the habitable zone? Will there be life on any of the planets one day?

There’s a point in every solar system’s development when it can no longer form planets. No more planets can form because there’s no more gas and dust available, and the expanding planetary possibilities are truncated. But the total mass of a solar system’s planets never adds up to the total mass of gas and dust available around the young star.

What happens to the mass, and why can’t more planets form?

March 22, 2024March 22, 2024 by Evan Gough

Finding Atmospheres on Red Dwarf Planets Will Take Hundreds of Hours of Webb Time

This illustration shows what exoplanet K2-18 b could look like based on science data. NASA’s James Webb Space Telescope examined the exoplanet and revealed the presence of carbon-bearing molecules. The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. But more extensive observations with the JWST are needed to understand its atmosphere with greater confidence. Image Credit: By Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)Science: Nikku Madhusudhan (IoA)

The JWST is enormously powerful. One of the reasons it was launched is to examine exoplanet atmospheres to determine their chemistry, something only a powerful telescope can do. But even the JWST needs time to wield that power effectively, especially when it comes to one of exoplanet science’s most important targets: rocky worlds orbiting red dwarfs.

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.

February 28, 2024February 28, 2024 by Evan Gough

Dwarf Galaxies Banished the Darkness and Lit Up the Early Universe

The JWST used gravitational lensing to search for the sources of light that triggered the Epoch of Reionization and brought darkness to an end. The white hazy blobs are galaxies in Pandora's Cluster, which acts as the gravitational lens. The red objects are the distant and ancient objects magnified by the lens, some of them warped into arcs. Many of them are early dwarf galaxies, some of them responsible for the Epoch of Reionization. Image Credit: NASA/ESA/CSA JWST

During the Universe’s Dark Ages, dense primordial gas absorbed and scattered light, prohibiting it from travelling. Only when the first stars and galaxies began to shine in energetic UV light did the Epoch of Reionization begin. The powerful UV light shone through the Universe and punched holes in the gas, allowing light to travel freely.

New observations with the James Webb Space Telescope reveal how it happened. The telescope shows that faint dwarf galaxies brought an end to the darkness.

February 22, 2024February 22, 2024 by Scott Alan Johnston

If Hycean Worlds Really Exist, What are Their Oceans Like?

Artist's impression of possible hycean world K2-18 b. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

Astronomers have been on the hunt for a new kind of exoplanet in recent years – one especially suited for habitability. They’re called hycean worlds, and they’re characterized by vast liquid water oceans and thick hydrogen-rich atmospheres. The name was coined in 2021 by Cambridge astronomer Nikku Madhusudhan, whose team got a close-up look at one possible hycean world, K2-18b, using the James Webb Space Telescope in 2023. In a newly accepted paper this January, Madhusudhan and coauthor Frances Rigby examined what the internal structure of hycean planets might look like, and what that means for the possibility of finding life within.