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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Webb Completes its First “Deep Field” With Nine Days of Observing Time. What did it Find?

This image taken by the James Webb Space Telescope highlights the region of study by the JWST Advanced Deep Extragalactic Survey (JADES). This area is in and around the Hubble Space Telescope’s Ultra Deep Field. Image Credit: NASA, ESA, CSA, and M. Zamani (ESA/Webb).

About 13 billion years ago, the stars in the Universe’s earliest galaxies sent photons out into space. Some of those photons ended their epic journey on the James Webb Space Telescope’s gold-plated, beryllium mirrors in the last few months. The JWST gathered these primordial photons over several days to create its first “Deep Field” image.

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Astronomers Directly Image Debris Disk and find a Jupiter-Sized Planet Orbiting a Sunlike Star

Astronomers with the SHINE collabortion observed a debris disk containing a Super-Jupiter around a young star. Credit: ALMA (ESO/NAOJ/NRAO); M. Weiss (NRAO/AUI/NSF)

According to the most widely-accepted theory, planetary systems form from large clouds of dust and gas that form disks around young stars. Over time, these disks accrete to create planets of varying size, composition, and distance from their parent star. In the past few decades, observations in the mid- and far-infrared wavelengths have led to the discovery of debris disks around young stars (less than 100 million years old). This has allowed astronomers to study planetary systems in their early history, providing new insight into how systems form and evolve.

This includes the SpHere INfrared survey for Exoplanets (SHINE) consortium, an international team of astronomers dedicated to studying star systems in formation. Using the ESO’s Very Large Telescope (VLT), the SHINE collaboration recently directly imaged and characterized the debris disk of a nearby star (HD 114082) in visible and infrared wavelengths. Combined with data from NASA’s Transiting Exoplanet Space Satellite (TESS), they were able to detect a gas giant many times the size of Jupiter (a “Super-Jupiter”) embedded within the disk.

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Webb Turns its Infrared Gaze on Mars

Graphic of Webb’s 2 NIRCam instrument images of Mars, taken on Sept. 5, 2022. Credit: NASA, ESA, CSA, STScI, Mars JWST/GTO team

The James Webb Space Telescope (JWST) is the most complex and sophisticated observatory ever deployed. Using its advanced suite of infrared instruments, coronographs, and spectrometers – contributed by NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA) – this observatory will spend the next ten to twenty years building on the achievements of its predecessor, the venerable Hubble. This includes exoplanet characterization, star and planet formation, and the formation and evolution of the earliest galaxies in the Universe.

However, one of the main objectives of the JWST is to study the planets, moons, asteroids, comets, and other celestial bodies here in the Solar System. This includes Mars, the first Solar planet to get the James Webb treatment! The images Webb took (recently released by the ESA) provide a unique perspective on Mars, showing what the planet looks like in infrared wavelengths. The data yielded by these images could provide new insight into Mars’ atmosphere and environment, complimenting decades of observations by orbiters, landers, rovers, and other telescopes.

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The Youngest Exoplanet Ever Seen?

Credit: ALMA (ESO/NAOJ/NRAO), S. Dagnello (NRAO/AUI/NSF)

According to the most widely-accepted theory by astronomers, planetary systems begin as massive clouds of gas and dust (aka. a nebula) that experience gravitational collapse at the center to form new stars. The remaining matter in the system forms a “circumplanetary disk” around the star, which gradually accretes to form young planets. Studying disks in the earliest stages of planetary formation could help answer some hard questions about how the Solar System formed over 4.5 billion years ago.

Studying these disks requires observatories capable of capturing light in the far-infrared part of the spectrum – precisely what the Atacama Large Millimeter/submillimeter Array (ALMA) was built for. While studying a young star (AS 209) located about 395 light-years from Earth in the constellation Ophiuchus, a team of scientists observed a circumplanetary disk that appeared to have a Jupiter-mass planet embedded in it. This could constitute the youngest exoplanet ever detected, and its continued study could provide a treasure-trove of data for astronomers.

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Now, We can Finally Compare Webb to Other Infrared Observatories

The evolution of infrared astronomy, from Spitzer to WISE to JWST. Image credit: Andras Gaspar.

The images released by the James Webb Space Telescope team last week aren’t officially ‘first light’ images from the new telescope, but in a way, it feels like they are. These stunning views provide the initial indications of just how powerful JWST will be, and just how much infrared astronomy is about to improve.

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Webb Has Almost Reached its Final, Coldest Temperature

Image: James Webb Space Telescope
NASA's James Webb Telescope, shown in this artist's conception, will provide more information about previously detected exoplanets. Beyond 2020, many more next-generation space telescopes are expected to build on what it discovers. Credit: NASA

 

Launched on December 25, 2021 from ESA’s launch site in Kourou, French Guiana aboard an Ariane 5 rocket, the James Webb Space Telescope (JWST) reached its final orbit at the L2 Lagrange point on January 24, 2022. It has since performed several operations to get it ready for its observing mission which should begin in about a month.

As part of getting it ready for its mission, NASA has been cooling off its instruments, such as the Mid-Infrared Instrument (MIRI), to operating temperatures. Now that they have reached that point, all that’s left to cool down are the mirrors.

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