Universe Today

Over the course of billions of years, the universe has steadily been evolving. Thanks to the expansion of the universe, we are able to “see” back in time to watch that evolution, almost from the beginning. But every once in a while we see something that doesn’t fit into our current understanding of how the universe should operate. That’s the case for a galaxy described in a new paper by PhD student Sijia Cai of Tsinghua University’s Department of Astronomy and their colleagues. They found a galaxy formed around 11 billion years ago that appears to be “metal-free”, indicating that it might contain a set of elusive first generation (Pop III) stars.

All of the proposals floating around out there for invoking dynamical dark energy are a little on the weak side. In many cases, they raise more questions than answers.

Researchers using the NASA/ESA/CSA James Webb Space Telescope have confirmed an actively growing supermassive black hole within a galaxy just 570 million years after the Big Bang. Part of a class of small, very distant galaxies that have mystified astronomers, CANUCS-LRD-z8.6 represents a vital piece of this puzzle that challenges existing theories about the formation of galaxies and black holes in the early Universe. The discovery connects early black holes with the luminous quasars we observe today.

Observations of a merging black hole further supports the Area Theorem of black hole thermodynamics, which states that the event horizon of a black hole produced by two merging black holes must have a surface area no less than the areas of the original two.

Tracking down black holes at the center of dwarf galaxies has proven difficult. In part that is because they have a tendency to “wander” and are not located at the galaxy’s center. There are plenty of galaxies that might contain such a black hole, but so far we’ve had insufficient data to confirm their existence. A new paper from Megan Sturm of Montana State University and her colleagues analyzed additional data from Chandra and Hubble on a set of 12 potential Active Galactic Nuclei (AGN) galaxy candidates. They were only able to confirm three, which highlights the difficulty in isolating these massive wanderers.

To be fair, all scientific models are in some sense wrong

Galaxies grow massive through mergers with other galaxies. Massive galaxies like the Milky Way and Andromeda not only merge with other large galaxies, they also absorb their much smaller satellite dwarf galaxies. But these smaller galaxies can become quenched long before they're absorbed, and new research examines this process at Andromeda (M31).

All motion is relative. That simple fact makes tracking the motion of distant objects outside our galaxy particularly challenging. For example, there has been a debate among astronomers for decades about the path that one of our nearest neighbors, the Large Magellanic Cloud (LMC), took over the last few billion years. A new paper from Scott Lucchini and Jiwon Jesse Hand from the Harvard Center for Astrophysics grapples with that question by using a unique technique - the paths of hypervelocity stars.

Let’s rewind the clock back…oh, I don’t know, let’s say a hundred years.

Observations of a supernova explosion have revealed its shape only one day after it was first detected. The exact nature of supernovae explosions are unclear and the subject of ongoing, detailed debate. These new observations with the European Southern Observatory's Very Large Telescope will advance the debate.

Astronomers have found more than 6,000 exoplanets in the Milky Way. They've even begun to characterize the atmospheres of some of them. But the Milky Way has consumed many of its dwarf satellites. How have exoplanets fared in these remnants? How are they different? To answer those questions, astronomers have to find some of these planets, and a new survey is poised to do just that.

At this point in history, astronomers and engineers who grew up watching Deep Impact and Armageddon, two movies about the destructive power of asteroid impacts, are likely in relatively high ranking positions at space agencies. Don’t Look Up also provided a more modern, though more pessimistic (or, unfortunately, realistic?), look at what might potentially happen if a “killer” asteroid is found on approach to Earth. So far, life hasn’t imitated art when it comes to potentially one of the most catastrophic events in human history, but most space enthusiasts agree that it's worth preparing for when it will. A new paper, available in pre-print on arXiv, from Maxime Devogèle of ESA’s Near Earth Object (NEO) Coordination Centre and his colleagues analyzes a dry run that happened around a year ago with the discovery of asteroid 2024 YR4.

In March of 2024 the [DESI collaboration](https://www.desi.lbl.gov/collaboration/) dropped a bombshell on the cosmological community: slim but significant evidence that dark energy might be getting weaker with time.

Swift observations with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) have revealed the explosive death of a star just as the blast was breaking through the star’s surface. For the first time, astronomers unveiled the shape of the explosion at its earliest, fleeting stage. This brief initial phase wouldn’t have been observable a day later and helps address a whole set of questions about how massive stars go supernova.

So I got an email from Adam Reiss. You know, the guy who was awarded the 2011 Nobel Prize in Physics along with Saul Perlmutter and Brian Schmidt for discovering the rate of cosmic expansion is accelerating. He pointed out a few issues with the decelerating Universe paper, and with his permission I'd like to share them with you.

Keep an eye on the sky Sunday night and early Monday morning for the Leonid meteors, and a possible second auroral storm. Once every other generation, the Lion roars. If skies are clear Monday morning, keep an eye out for one of the best annual November showers, the Leonid meteors. Also as an extra treat, the skies may stream with aurora once again.

Most people interested in space exploration already know lunar dust is an absolute nightmare to deal with. We’re already reported on numerous potential methods for dealing with it, from 3D printing landing pads so we don’t sand blast everything in a given area when a rocket lands, to using liquid nitrogen to push the dust off of clothing. But the fact remains that, for any long-term presence on the Moon, dealing with the dust that resides there is one of the most critical tasks. A new paper from Dr. Slava Turyshev of NASA’s Jet Propulsion Laboratory, who is enough of a polymath that our last article about his research was covering a telescope at the solar gravitational lens, updates our understanding of the physical properties of lunar dust, providing more accurate information that engineers can use to design the next round of rovers and infrastructure to support human expansion to our nearest neighbor.

The Shenzhou-20 mission's three-person crew has returned home after more than a week of delays caused by damage to their spacecraft, allegedly caused by an impact with a tiny piece of space debris.

Astronomers have discovered that the famous Pleiades star cluster, otherwise known as the "Seven Sisters" is actually the bright core of a sprawling family of stars spread across nearly 2,000 light years. By combining stellar spin measurements with precise motion tracking, researchers identified over 3,000 related stars and revealed the Pleiades is twenty times larger than previously thought.

Astronomers have discovered that our Solar System is moving through the universe more than three times faster than cosmological models predict, a finding that challenges fundamental assumptions about how the universe works. By analysing the distribution of distant radio galaxies using advanced statistical methods, the team detected motion so unexpectedly rapid it earned the rare five sigma statistical significance that scientists consider definitive evidence.