A Solo Brown Dwarf Found With Auroras

This artist concept portrays the brown dwarf W1935, which is located 47 light-years from Earth. Astronomers using NASA’s James Webb Space Telescope found infrared emission from methane coming from W1935, generating an aurora, a very unexpected discovery. Credit: NASA, ESA, CSA, Leah Hustak (STScI)

Astronomers have used JWST to find a brown dwarf with polar auroras like the Earth, or Jupiter. This is surprising because the brown dwarf, dubbed W1935, is a free-floating object, meaning it isn’t part of another star system. Therefore, there’s no solar wind available to generate any Northern Lights. Instead, the auroras are seemingly generated from methane emissions in the planet’s atmosphere, interacting with the interstellar plasma. Another theory is that it perhaps has an active but unseen moon contributing to the emissions.

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Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?

Obtaining accurate redshift measurements is a challenge, even with telescopes like Webb. Credit: NASA

One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its light has been traveling through space.

This is the purpose of the Cosmic Evolution Early Release Science Survey (CEERS), a collaborative research group that analyzes Webb data to learn more about galactic evolution. These galaxies are known as “high-redshift,” meaning that their light emissions are redshifted all the way into the infrared spectrum. Galaxies that existed ca. 13 billion years ago can only be observed in the near-infrared spectrum, which is now possible thanks to Webb’s Near-Infrared Camera (NIRCam). Even so, obtaining accurate redshift measurements from such distant galaxies is a very tricky, and requires advanced techniques.

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JWST Reveals a Newly-Forming Double Protostar

This new Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope reveals intricate details of the Herbig Haro object 797 (HH 797). HH 797 dominates the lower half of this image. The bright infrared objects in the upper portion of the image are thought to host two further protostars. This image was captured with Webb’s Near-InfraRed Camera (NIRCam). Image Credit: JWST/CSA/ESA/NASA

As our newest, most perceptive eye on the ongoing unfolding of the cosmos, the James Webb Space Telescope is revealing many things that were previously unseeable. One of the space telescope’s science goals is to expand our understanding of how stars form. The JWST has the power to see into the cocoons of gas and dust that hide young protostars.

It peered inside one of these cocoons and showed us that what we thought was a single star is actually a binary star.

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JWST Sees Four Exoplanets in a Single System

This artist’s rendering shows the star HR 8799 and one of its four planets, HR 8799c. It illustrates the system at an early stage of evolution. It also shows the star's dusty disk and rocky inner planets. Credit: Dunlap Institute for Astronomy & Astrophysics

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

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We Should Be Looking for Small, Hot Dyson Spheres

A Type II civilization is one that can directl harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

In 1960, legendary physicist Freeman Dyson published his seminal paper “Search for Artificial Stellar Sources of Infrared Radiation,” wherein he proposed that there could be extraterrestrial civilizations so advanced that they could build megastructures large enough to enclose their parent star. He also indicated that these “Dyson Spheres,” as they came to be known, could be detected based on the “waste heat” they emitted at mid-infrared wavelengths. To this day, infrared signatures are considered a viable technosignature in the Search for Extraterrestrial Intelligence (SETI).

So far, efforts to detect Dyson Spheres (and variation thereof) by their “waste heat” signatures have come up empty, leading some scientists to recommend tweaking the search parameters. In a new paper, astronomy and astrophysics Professor Jason T. Wright of the Center for Exoplanets and Habitable Worlds and the Penn State Extraterrestrial Intelligence Center (PSTI) recommends that SETI researchers refine the search by looking for indications of activity. In other words, he recommends looking for Dyson Spheres based on what they could be used for rather than just heat signatures.

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The Seasons on Saturn are Changing. It's Time to Say Goodbye to Its North Pole for a Few Years

Saturn, as seen by the James Webb Space Telescope's MIRI instrument, showing various portions of the planet's atmosphere. superimposed on an full image taken by the Hubble Space Telescope. Credit: NASA/ESA/Univ. Leicester/L.N. Fletcher/O. King

Just like Earth, Saturn goes through seasons because of its axial tilt. But a year on Saturn lasts 30 Earth years, so each of its seasons lasts 7.5 years. Right now, it is late summer on Saturn’s northern hemisphere, so again, just like Earth is currently heading for northern autumn equinox in September, Saturn is heading for northern autumn equinox a little later, in 2025.

Before Saturn’s north pole enters its extended polar winter – rendering it inaccessible for observations — astronomers are taking advantage of being able to study this area with the James Webb Space Telescope, which became operational just over a year ago.

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Twinkling Stars Supply the Dust That Leads to Life

Artist’s impression of the star in its multi-million year long and previously unobservable phase as a large, red supergiant. Credit: CAASTRO / Mats Björklund (Magipics)

When low to medium-mass stars exhaust their supply of hydrogen, they exit their main sequence phase and expand to become red giants – what is known as the Asymptotic Giant Branch (AGB) phase. Stars in this phase of their evolution become variable (experiences changes in brightness) to shed their outer lays, spreading dust throughout the interstellar medium (ISM) that is crucial to the development of planetary nebulas and protoplanetary systems. For decades, astronomers have sought to better understand the role Red Giant stars play.

Studying interstellar and protoplanetary dust is difficult because it is so faint in visible light. Luckily, this dust absorbs light and radiates brightly in the infrared (IR), making it visible to IR telescopes. Using archival data from now-retired Akari and Wide-field Infrared Survey Explorer (WISE) missions, a team of Japanese astronomers conducted the first long-period survey of dusty AGBs and observed that the variable intensity of these stars coincides with the amount of dust they produce. Since this dust plays an important role in the formation of planets, this study could shed light on the origins of life.

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JWST Sees Frozen Water, Ammonia, Methane and Other Ices in a Protostellar Nebula

A large, dark cloud is contained within the frame. In its top half it is textured like smoke and has wispy gaps, while at the bottom and at the sides it fades gradually out of view. On the left are several orange stars: three each with six large spikes, and one behind the cloud which colours it pale blue and orange. Many tiny stars are visible, and the background is black.
This image by the James Webb Space Telescope’s Near-InfraRed Camera (NIRCam) features the central region of the Chameleon I dark molecular cloud, which resides 630 light years away. Credit: NASA, ESA, CSA, and M. Zamani (ESA/Webb); Science: M. K. McClure (Leiden Observatory), F. Sun (Steward Observatory), Z. Smith (Open University), and the Ice Age ERS Team.

Want to build a habitable planet? Then you’ll need various and sundry ingredients such as carbon, hydrogen oxygen, nitrogen and sulfur. The James Webb Space Telescope has found the building blocks for these key ingredients in the colds depths of a distant protostellar nebula called the Chameleon I molecular cloud. Scientists say the discovery of these proto-ingredients allows astronomers to examine the simple icy molecules that one day will be incorporated into future exoplanets.

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For the First Time, Astronomers Spot Stars in Galaxies that Existed Just 1 Billion Years After the Big Bang

Artist impression of a powerful young quasar. Credit: ESO/M. Kornmesser Credit: ESO/M. Kornmesser

Since it launched on December 25th, 2021 (quite the Christmas present!), the James Webb Space Telescope (JWST) has taken the sharpest and most detailed images of the Universe, surpassing even its predecessor, the venerable Hubble Space Telescope! But what is especially exciting are the kinds of observations we can look forward to, where the JWST will use its advanced capabilities to address some of the most pressing cosmological mysteries. For instance, there’s the problem presented by high-redshift supermassive black holes (SMBHs) or brightly-shining quasars that existed during the first billion years of the Universe.

To date, astronomers have not been able to determine how SMBHs could have formed so soon after the Big Bang. Part of the problem has been that, until recently, stars in host galaxies with redshift values of Z>2 (within 10.324 billion light-years) have been elusive. But thanks to the JWST, an international team of astronomers recently observed stars in quasars at Z>6 (within 12.716 billion light-years) for the first time. Their observations could finally allow astronomers to assess the processes in early quasars that governed the formation and evolution of the first SMBHs.

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Astronomers Spot Three Interacting Systems with Twin Discs

Artist's conceptualization of the dusty TYC 8241 2652 system as it might have appeared several years ago when it was emitting large amounts of excess infrared radiation. Credit: Gemini Observatory/AURA artwork by Lynette Cook. https://www.gemini.edu/node/11836

According to the most widely-accepted theory about star formation (Nebular Hypothesis), stars and planets form from huge clouds of dust and gas. These clouds undergo gravitational collapse at their center, leading to the birth of new stars, while the rest of the material forms disks around it. Over time, these disks become ring structures that accrete to form systems of planets, planetoids, asteroid belts, and Kuiper belts. For some time, astronomers have questioned how interactions between early stellar environments may affect their formation and evolution.

For instance, it has been theorized that gravitational interactions with a passing star or shock waves from a supernova might have triggered the core collapse that led to our Sun. To investigate this possibility, an international team of astronomers observed three interacting twin disc systems using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the ESO’s Very Large Telescope (VLT). Their findings show that due to their dense stellar environments, gravitational encounters between early-stage star systems play a significant role in their evolution.

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