Universe Today

August 31, 2024August 31, 2024 by Mark Thompson

By Watching the Sun, Astronomers are Learning More about Exoplanets

Illustration of the Sun seen from Mercury

Watching the Olympics recently and the amazing effort of the hammer throwers was a wonderful demonstration of the radial velocity method that astronomers use to detect exoplanets. As the hammer spins around the athlete, their body and head bobs back and forth as the weight from the hammer tugs upon them. In the same way we can detect the wobble of a star from the gravity of planets in orbit. Local variations in the stars can add noise to the data but a team of researchers have been studying the Sun to help next-generation telescopes detect more Earth-like planets.

August 31, 2024August 31, 2024 by Laurence Tognetti

Coronal Loops-Digital Art Combination Captures Power of the Sun, Rendered by Andrew McCarthy

A composite image comprised of the Sun's surface, corona, and digitally-added coronal loops rendered by Andrew McCarthy. (Credit: Andrew McCarthy)

Our Sun is one of the most fascinating objects in the universe and photographing it with specialized equipment to capture its splendor and beauty has become increasingly more common around the world. This is most evident with the work obtained by renowned astrophotographer, Andrew McCarthy (@AJamesMcCarthy), who owns Cosmic Background Studios in Florence, Arizona.

On July 27, 2024, McCarthy posted an image of the Sun on X (formerly known as Twitter) taken with his specialized equipment designed to safely photograph our life-giving star, which revealed active coronal loops and plasma within the solar chromosphere that are some of the many intriguing features of the Sun. However, McCarthy is quick to mention in his post that this image isn’t entirely genuine, but a combination of several attributes.

August 31, 2024August 31, 2024 by Mark Thompson

Estimating the Basic Settings of the Universe

This snapshot compares the distribution of galaxies in a simulated universe used to train SimBIG (right) to the galaxy distribution seen in the real universe (left). Bruno Régaldo-Saint Blancard/SimBIG collaboration

The Standard Model describes how the Universe has evolved at large scale. There are six numbers that define the model and a team of researchers have used them to build simulations of the Universe. The results of these simulations were then fed to a machine learning algorithm to train it before it was set the task of estimating five of the cosmological constants, a task which it completed with incredible precision.

August 31, 2024August 30, 2024 by Carolyn Collins Petersen

Dark Matter Could Have Driven the Growth of Early Supermassive Black Holes

An image from the Event Horizon Telescope shows lines of polarization, a signature of magnetic fields, around the shadow of the Milky Way's central supermassive black hole. Astronomers want to know how massive black holes like this one formed early in cosmic history. (Credit: EHT Collaboration)

The James Webb Space Telescope (JWST) keeps finding supermassive black holes (SMBH) in the early Universe. They’re in active galactic nuclei seen only 500,000 years after the Big Bang. This was long before astronomers thought they could exist. What’s going on?

August 30, 2024August 30, 2024 by Mark Thompson

If Gravitons Exist, this Experiment Might Find Them

It’s thought that gravity consists of minute quantum building blocks called gravitons, but so far they have been too elusive to observe. A new result from Pikovski’s Research Group now shows that next-generation quantum sensors can catch a single one.

There are four fundamental forces in the Universe; strong, weak, electromagnetic and gravity. Quantum theory explains three of the four through the interaction of particles but science has yet to discover a corresponding particle for gravity. Known as the ‘graviton’, the hypothetical gravity particle is thought to constitute gravitational waves but it hasn’t been detected in gravity wave detector. A new experiment hopes to change that using an acoustic resonator to identify individual gravitons and confirm their existence.

August 30, 2024August 30, 2024 by Evan Gough

How Vegetation Could Impact the Climate of Exoplanets

Image of Earth from 2020, over the South Pacific Ocean from the EPIC camera on the DSCOVR satellite. Many things affect Earth's albedo, including clouds, snow cover, and vegetation. How does exoplanet vegetation affect albedo and climate? Credit: NASA/NOAA

The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable.

New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life.

August 30, 2024August 30, 2024 by Carolyn Collins Petersen

A New Test Proves How to Make the Event Horizon Telescope Even Better

This image shows the Atacama Large Millimeter/submillimeter Array (ALMA) looking up at the supermassive black hole at our galactic centre. ALMA is part of the Event Horizon Telescope. Courtesy EHT. — This image shows the Atacama Large Millimeter/submillimeter Array (ALMA) looking up at the supermassive black hole at our galactic centre. ALMA is part of the Event Horizon Telescope. Courtesy EHT and ESO.

Want a clear view of a supermassive black hole’s environment? It’s an incredible observational challenge. The extreme gravity bends light as it passes through and blurs the details of the event horizon, the region closest to the black hole. Astronomers using the Event Horizon Telescope (EHT) just conducted test observations aimed at “deblurring” that view.

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 30, 2024August 30, 2024 by Mark Thompson

New Limits on Dark Matter

LZ’s central detector, the time projection chamber, in a surface lab clean room before delivery underground. Credit: Matthew Kapust/Sanford Underground Research Facility

As it’s name suggests, dark matter is dark! That means it’s largely invisible to us and only detectable through its interaction with gravity. One of the leading theories to explain the stuff that makes up the majority of the matter in the Universe are WIMPs, Weakly Interacting Massive Particles. They are just theories though and none have been detected. An exciting new experiment called LUX-ZEPLIN has just completed 280 days of collecting data but still, no WIMPs have been detected above 9 Gev/c2. There are plans though to narrow the search.

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!