The Webb Discovers a Rich Population of Brown Dwarfs Outside the Milky Way

Near the outskirts of the Small Magellanic Cloud, a satellite galaxy roughly 200 000 light-years from Earth, lies the young star cluster NGC 602, which is featured in this new image from the NASA/ESA/CSA James Webb Space Telescope. This image includes data from Webb’s NIRCam (Near-InfraRed Camera) and MIRI (Mid-InfraRed Instrument). Image Credit: ESA/Webb, NASA & CSA, P. Zeidler, E. Sabbi, A. Nota, M. Zamani (ESA/Webb)

This stunning image of a star cluster in the Small Magellanic Cloud (SMC) is more than just a pretty picture. It’s part of a scientific effort to understand star formation in an environment different from ours. The young star cluster is called NGC 602, and it’s very young, only about 2 or 3 million years old.

Continue reading “The Webb Discovers a Rich Population of Brown Dwarfs Outside the Milky Way”

Webb Observations Shed New Light on Cosmic Reionization

A simulation of galaxies during the era of deionization in the early Universe. Credit: M. Alvarez, R. Kaehler, and T. AbelCredit: M. Alvarez, R. Kaehler, and T. Abel

The “Epoch of Reionization” was a critical period for cosmic evolution and has always fascinated and mystified astronomers. During this epoch, the first stars and galaxies formed and reionized the clouds of neutral hydrogen that permeated the Universe. This ended the Cosmic Dark Ages and led to the Universe becoming “transparent,” what astronomers refer to as “Cosmic Dawn.” According to our current cosmological models, reionization lasted from 380,000 to 1 billion years after the Big Bang. This is based on indirect evidence since astronomers have been unable to view the Epoch of Reionization directly.

Investigating this period was one of the main reasons for developing the James Webb Space Telescope (JWST), which can pierce the veil of the “dark ages” using its powerful infrared optics. However, observations provided by Webb revealed that far more galaxies existed in the early Universe than previously expected. According to a recent study, this suggests that reionization may have happened more rapidly and ended at least 350 million years earlier than our models predict. Once again, the ability to peer into the early Universe has produced tensions with prevailing cosmological theories.

Continue reading “Webb Observations Shed New Light on Cosmic Reionization”

A Black Hole has Almost Halted Star Formation in its Galaxy

This is a quiescent galaxy in the early Universe named GS-10578 but nicknamed ‘Pablo’s Galaxy’. It has an SMBH in its center, and astronomers have used the NASA/ESA James Webb Space Telescope to confirm that supermassive black holes can starve their host galaxies of the fuel they need to form new stars. Image Credit: JADES Collaboration

When the James Webb Space Telescope was launched on Christmas Day in 2021, it faced a whole host of intriguing questions. By the time it finally launched, astronomers had a big list of targets begging for the type of detailed observations that only the powerful infrared space telescope could perform. One of the targets was an ancient, massive galaxy that’s basically dead and forms no new stars.

The results are in, and an international team of astronomers know what happened to the quiescent galaxy.

Continue reading “A Black Hole has Almost Halted Star Formation in its Galaxy”

Book Review: Is Earth Exceptional?

Book
On sale now. Credit: Hachette Books.

A new book looks at the latest scientific insights versus a key question in astronomy and space science.

It’s tough to answer a scientific question, with a just data point of one. How special are we, and how common (or rare) is the story of how life arose on the Earth in the grander drama of the cosmos?

A new book out this week entitled Is Earth Exceptional? The Quest for Cosmic Life by Mario Livio and Jack Szostak looks at the scientific state of answering this key question. The book offers a sweeping view of the nascent science of astrobiology, a multi-disciplinary field melding biology, chemistry, astronomy and more.

Continue reading “Book Review: Is Earth Exceptional?”

Remember those Impossible Galaxies Found by JWST? It Turns Out They Were Possible After All

This is a small portion of the field observed by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) for the Cosmic Evolution Early Release Science (CEERS) survey. It is filled with galaxies. The light from some of them has traveled for over 13 billion years to reach the telescope. Credit: NASA, ESA, CSA, Steve Finkelstein (University of Texas at Austin)

When the James Webb Space Telescope provided astronomers with a glimpse of the earliest galaxies in the Universe, there was some understandable confusion. Given that these galaxies existed during “Cosmic Dawn,” less than one billion years after the Big Bang, they seemed “impossibly large” for their age. According to the most widely accepted cosmological model—the Lambda Cold Dark Matter (LCDM) model—the first galaxies in the Universe did not have enough time to become so massive and should have been more modestly sized.

This presented astronomers with another “crisis in cosmology,” suggesting that the predominant model about the origins and evolution of the Universe was wrong. However, according to a new study by an international team of astronomers, these galaxies are not so “impossibly large” after all, and what we saw may have been the result of an optical illusion. In short, the presence of black holes in some of these early galaxies made them appear much brighter and larger than they actually were. This is good news for astronomers and cosmologists who like the LCDM the way it is!

Continue reading “Remember those Impossible Galaxies Found by JWST? It Turns Out They Were Possible After All”

Webb Discovers Six New “Rogue Worlds” that Provide Clues to Star Formation

This stunning new mosaic of images from the NASA/ESA/CSA James Webb Space Telescope showcases the nearby star-forming cluster, NGC 1333. Credit: ESA/Webb, NASA & CSA, A. Scholz, K. Muzic, A. Langeveld, R. Jayawardhana

Rogue Planets, or free-floating planetary-mass objects (FFPMOs), are planet-sized objects that either formed in interstellar space or were part of a planetary system before gravitational perturbations kicked them out. Since they were first observed in 2000, astronomers have detected hundreds of candidates that are untethered to any particular star and float through the interstellar medium (ISM) of our galaxy. In fact, some scientists estimate that there could be as many as 2 trillion rogue planets (or more!) wandering through the Milky Way alone.

In recent news, a team of astronomers working with the James Webb Space Telescope (JWST) announced the discovery of six rogue planet candidates in an unlikely spot. The planets, which include the lightest rogue planet ever identified (with a debris disk around it), were spotted during Webb‘s deepest survey of the young nebula NGC 1333, a star-forming cluster about a thousand light-years away in the Perseus constellation. These planets could teach astronomers a great deal about the formation process of stars and planets.

Continue reading “Webb Discovers Six New “Rogue Worlds” that Provide Clues to Star Formation”

Fast-Tracking the Search for Habitable Worlds

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)
Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

Modern astronomy would struggle without AI and machine learning (ML), which have become indispensable tools. They alone have the capability to manage and work with the vast amounts of data that modern telescopes generate. ML can sift through large datasets, seeking specified patterns that would take humans far longer to find.

The search for biosignatures on Earth-like exoplanets is a critical part of contemporary astronomy, and ML can play a big role in it.

Continue reading “Fast-Tracking the Search for Habitable Worlds”

Why is JWST Having So Much Trouble with the TRAPPIST-1 System?

A new step-by-step roadmap describes how to improve the efficiency of data gathering with the JWST to benefit the astronomy community at large. “Our hope now is that a large-scale community effort guided by the roadmap can be initiated to yield deliverables at a timely pace,” says MIT Associate Professor Julien de Wit. Credits:Image components courtesy of NASA/JPL-Caltech.

When the James Webb Space Telescope was launched it came with a fanfare expecting amazing things, much like the Hubble Space Telescope. One of JWST’s most anticipated target was TRAPPIST-1. This inconspicuous star is host to seven Earth-sized planets, with at least three in the habitable zone. The two inner planets are airless worlds but so far there has been no word of the third planet, the first in the habitable zone. The question is why and what makes it so tricky to observe?

Continue reading “Why is JWST Having So Much Trouble with the TRAPPIST-1 System?”

New Images From Webb Reveal Jupiter's Complex Atmosphere

New observations of the Great Red Spot on Jupiter have revealed that the planet’s atmosphere above and around the infamous storm is surprisingly interesting and active. Credit: ESA

The James Webb Space Telescope (JWST) has accomplished some spectacular feats since it began operations in 2021. Thanks to its sensitivity in the near- and mid-infrared wavelengths, it can take detailed images of cooler objects and reveal things that would otherwise go unnoticed. This includes the iconic image Webb took of Jupiter in August 2022, which showed the planet’s atmospheric features (including its polar aurorae and Great Red Spot) in a new light. Using Webb, a team of European astronomers recently observed the region above the Great Red Spot and discovered previously unseen features.

Continue reading “New Images From Webb Reveal Jupiter's Complex Atmosphere”

Do Planets Have the Raw Ingredients for Life? The Answer is in their Stars

Illustration of the Plato Observatory

Finding planets that already have, or have the ingredients for intelligent life is a real challenge. It is exciting that new telescopes and spacecraft are in development that will start to identify candidate planets. Undertaking these observations will take significant amounts of telescope time so we need to find some way to prioritise which ones to look at first. A new paper has been published that suggests we can study the host stars first for the necessary raw elements giving a more efficient way to hunt for similar worlds to Earth. 

Continue reading “Do Planets Have the Raw Ingredients for Life? The Answer is in their Stars”