Astronomy Archives

September 1, 2024September 1, 2024 by Scott Alan Johnston

Gravitational Wave Observatories Could Detect Primordial Black Holes Speeding Through the Solar System

Artist illustration of primordial black holes. NASA's Goddard Space Flight Center

Cosmologists have long hypothesized that the conditions of the early universe could have caused the formation of black holes not long after the Big Bang. These ‘primordial black holes’ have a much wider mass range than those that formed in the later universe from the death of stars, with some even condensed to the width of a single atom.

August 30, 2024August 30, 2024 by David Dickinson

ESA Cluster Satellite to Reenter in Early September

The first of a set of groundbreaking Cluster satellites is set for a controlled reentry next week.

The European Space Agency is paving the way in controlled reentry technology. ESA recently announced that plans to terminate the first of four Cluster satellites is about to come to fruition in early September, with the reentry of Salsa.

August 29, 2024August 31, 2024 by Matt Williams

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!

August 29, 2024August 29, 2024 by Matt Williams

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.

August 29, 2024August 29, 2024 by Evan Gough

The Rubin Observatory Will Unleash a Flood of NEO Detections

The Vera Rubin Observatory is poised to begin observations next year. It could detect 130 Near Earth Objects each night. Image Credit: Rubin Observatory/NSF/AURA/B. Quint

After about 10 years of construction, the Vera Rubin Observatory (VRO) is scheduled to see its first light in January 2025. Once it’s up and running, it will begin its Legacy Survey of Space and Time (LSST), a decade-long effort to photograph the entire visible sky every few nights. It’ll study dark energy and dark matter, map the Milky Way, and detect transient astronomical events and small Solar System objects like Near Earth Objects (NEOs).

New research shows the LSST will detect about 130 NEOs per night in the first year of observations.

August 27, 2024August 27, 2024 by Matt Williams

Massive Stars Shine in This Ultraviolet View From Hubble

NGC 346 is nestled within the Small Magellanic Cloud, a small satellite galaxy to our Milky Way. Credit: NASA/ESA/STScI/ Gladys Kober

Just outside the Milky Way Galaxy, roughly 210,000 light-years from Earth, there is the dwarf galaxy known as the Small Magellanic Cloud (SMC). Measuring about 18,900 light-years in diameter and containing roughly 3 billion stars, the SMC and its counterpart – the Large Magellanic Cloud (LMC) – orbit the Milky Way as satellite galaxies. Scientists are particularly interested in these satellites because of what they can teach us about star formation and the process where galaxies evolve through mergers, which is something the Milky Way will do with these two galaxies someday.

Another interesting feature of the SMC is the spectacular star cluster known as NGC 346, located near the center of the brightest star-forming region in the SMC, the hydrogen-rich nebula designated N66. Yesterday, NASA released a new image of this star cluster acquired by the venerable Hubble Space Telescope, which provides a unique and breathtaking view of this star cluster. These images were made possible thanks to Hubble’s sharp resolution and unique ability to make sensitive ultraviolet observations.

August 27, 2024August 21, 2024 by Paul M. Sutter

The Hardest Bias in Astronomy

An artist's illustration of a chaotic young solar system. Image Credit: Tobias Stierli, flaeck / PlanetS

A nasty sort of bias called Malmquist bias affects almost every astronomical survey, and the only solution is to…keep doing surveys.

August 26, 2024August 26, 2024 by Mark Thompson

X-Ray Telescopes Could Study Exoplanets Too

Exoplanets are often discovered using the transit method (over three quarters of those discovered have been found this way.) The same transit technique can be used to study them, often revealing detail about their atmosphere. The observations are typically made in visible light or infrared but a new paper suggests X-rays may be useful too. Stellar wind interactions with the planet’s atmosphere for example would lead to X-ray emissions revealing information about the atmosphere. As we further our exploration of exoplanets we develop our understanding of our own Solar System and ultimately, the origins of life in the Universe.

August 26, 2024August 21, 2024 by Paul M. Sutter

Life Needs Black Holes to Survive

Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

Life is rare, and it requires exactly the right environmental mix to establish itself. And there’s one surprising contributor to that perfect mix: gigantic black holes.

August 25, 2024August 21, 2024 by Paul M. Sutter

What Makes a Supercluster?

Illustration of the Laniakea Supercluster. Credit: Andrew Z. Colvin

By eye, it’s impossible to pick out the exact boundaries of the superclusters, which are among the largest structures in the universe. But that’s because they are not defined by their edges, but by the common motion of their components.