Universe Today

January 15, 2025January 15, 2025 by Andy Tomaswick

Astronomers See Flares Coming from the Milky Way’s Supermassive Black Hole

This artist’s conception of the mid-IR flare in Sgr A* captures the variability, or changing intensity, of the flare as the black hole’s magnetic field lines bunch together. This bunching results in magnetic reconnection, which produces particles and energy that spiral along the magnetic field lines until they cool and release their energy, spiking the intensity of the flare. Credit: CfA/Melissa Weiss

There’s plenty of action at the center of the galaxy, where a supermassive black hole (SMBH) known as Sagittarius A* (Sgr A*) literally holds the galaxy together. Part of that action is the creation of gigantic flares from Sgr A*, which can give off energy equivalent to 10 times the Sun’s annual energy output. However, scientists have been missing a key feature of these flares for decades – what they look like in the mid-infrared range. But now, a team led by researchers at Harvard’s Center for Astrophysics and the Max Planck Institute for Radio Astronomy has published a paper that details what a flare looks like in those frequencies for the first time.

January 14, 2025January 14, 2025 by Carolyn Collins Petersen

Earth’s Temporary Moon Might Have Come from THE Moon

The orbit of Near Earth Asteroid 2024 PT5. This asteroid may have once been part of the Moon. Courtesy NASA.

A tiny asteroid loitering in a near-Earth orbit for a few months last year may have an intriguing origin on our Moon. Its characteristics led scientists to ask: is it a chip off the old lunar block, making a pass by Earth for a visit?

January 14, 2025January 11, 2025 by Paul M. Sutter

Galaxy Cores May be Giant Fuzzy Dark Stars

This striking image was taken by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3, a powerful instrument installed on the telescope in 2009. WFC3 is responsible for many of Hubble’s most breathtaking and iconic photographs, including Pictures of the Week. Shown here, NGC 7773 is a beautiful example of a barred spiral galaxy. A luminous bar-shaped structure cuts prominently through the galaxy's bright core, extending to the inner boundary of NGC 7773's sweeping, pinwheel-like spiral arms. Astronomers think that these bar structures emerge later in the lifetime of a galaxy, as star-forming material makes its way towards the galactic centre — younger spirals do not feature barred structures as often as older spirals do, suggesting that bars are a sign of galactic maturity. They are also thought to act as stellar nurseries, as they gleam brightly with copious numbers of youthful stars. Our galaxy, the Milky Way, is thought to be a barred spiral like NGC 7773. By studying galactic specimens such as NGC 7773 throughout the Universe, researchers hope to learn more about the processes that have shaped — and continue to shape — our cosmic home.

A fuzzy form of dark matter may clump up to become the cores of galaxies, according to new research.

January 14, 2025January 14, 2025 by Mark Thompson

This Quasar Helped End the Dark Ages of the Universe

(AI-generated image created with researcher illustration, edited by Michael S. Helfenbein)

After the Big Bang came the Dark Ages, a period lasting hundreds of millions of years when the universe was largely without light. It ended in the epoch of reionization when neutral hydrogen atoms became charged for the first time and the first generation of stars started to form. The question that has perplexed astronomers is what caused the first hydrogen atoms to charge. A team of researchers have observed an early quasar that pumped out enormous amounts of x-ray radiation helping to drive the reionization.

January 14, 2025January 14, 2025 by Evan Gough

Webb Provides an Explanation for “Little Red Dots”

A team of astronomers sifted through James Webb Space Telescope data from multiple surveys to compile one of the largest samples of “little red dots” (LRDs) to date. From their sample, they found that these mysterious red objects that appear small on the sky emerge in large numbers around 600 million years after the big bang and undergo a rapid decline in quantity around 1.5 billion years after the big bang. Image Credit: NASA, ESA, CSA, STScI, Dale Kocevski (Colby College)

When a new space telescope is launched, it’s designed to address specific issues in astronomy and provide critical answers to important questions. The JWST was built with four overarching science goals in mind. However, when anticipating new telescopes, astronomers are quick to point out that they’re also excited by the unexpected discoveries that new telescopes make.

There has been no shortage of unexpected discoveries regarding the JWST, especially regarding the very early Universe.

January 14, 2025January 14, 2025 by Mark Thompson

Astronomers Reveal the 3D Structure of the Ring Nebula

The Ring Nebula as captured in visible light by Hubble Space Telescope, left; in radio emission from CO molecules by the Submillimeter Array (SMA), center; and in the infrared by the James Webb Space Telescope (JWST), right. The image is overlaid with contours of emission from CO that is moving perpendicular to our sight line, showing how the molecular gas imaged by the SMA envelopes the ionized gas imaged by JWST.

I’ve lost count of the number of times I have seen the Ring Nebula. It’s a favourite amongst stargazers around the globe and is surely one of the most well known objects in the night sky. The remains of a Sun-like star, its outer layers have drifted out into space leaving behind a the stellar corpse, a white dwarf. It looks like a giant smoke ring in the sky but what is its true shape? A team of astronomers have mapped carbon monoxide that surrounds the nebula and built a 3D model to reveal its shape.

January 14, 2025January 14, 2025 by Andy Tomaswick

It’s Official, 2024 Was the Hottest Year on Record

Climate scientists must fear sounding like a broken record when discussing new record temperatures yearly. But once again, last year was the hottest one ever recorded, according to a new study by NASA scientists.

January 14, 2025January 14, 2025 by Evan Gough

The Webb Shows Us Where Cosmic Dust Comes From

Concentric rings of dust form around the pair of binary stars named Wolf-Rayet 140. The dust is formed when the stellar winds from the stars slam into each other every few years. Image Credit: NASA, ESA, CSA, STScI, JPL-Caltech

Carbon-rich cosmic dust comes from different sources and spreads out into space, where it’s necessary for life and for the formation of rocky planets like ours. When astronomers aim their telescopes at objects in the sky, they often have to contend with this cosmic dust that obscures their targets and confounds their observations.

One reason the JWST was built is to see through some of this dust with its infrared vision and unlock new insights into astrophysical processes. In new work, the JWST was tasked with observing the dust itself.

January 14, 2025January 14, 2025 by Carolyn Collins Petersen

Jupiter’s Clouds Contain Smoggy Ammonium Hydrosulphide, Not Ammonia Ice

Jupiter and Saturn images from VLT/MUSE observations in March 2020. They show Jupiter's clouds as well as those in Saturn's atmosphere. Courtesy Irwin, et al. 2026, JGR Planets.

Jupiter’s clouds aren’t what we thought they were. Planetary atmosphere experts have studied them for many years, uncovering new and puzzling mysteries. Recently, several researchers banded together to solve a long-standing mystery about those clouds. It turns out they aren’t made of ammonia ice, which is what everyone has thought for years. Instead, they seem to be largely a mix of smog and ammonium hydrosulfide. That compound forms in the atmosphere as hydrogen sulfide gas passes through ammonia.

January 14, 2025January 14, 2025 by Brian Koberlein

Here's How We Could Measure the Mass of SgrA* to Within One Solar Mass

Image of the supermassive black hole Sag A* seen in polarized light. Credit: EHT Collaboration

There is a gravitational monster at the heart of our galaxy. Known as Sagittarius A*, it is a supermassive black hole with a mass of more than four million Suns. Long-term observations of the stars closely orbiting Sag A* place it at about 4.3 solar masses, give or take 100,000 or so. Observations of light near its horizon by the Event Horizon Telescope pin the mass down to 4.297 solar masses, give or take about 10,000. Those results are astoundingly precise given how difficult the mass is to measure, but suppose we could determine the mass of our galaxy’s black hole to within a single solar mass. That might be possible with gravitational wave astronomy.