Mark Thompson, Author at Universe Today

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 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 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 29, 2024 by Mark Thompson

For Their Next Trick, Gravitational Wave Observatories Could Detect Collapsing Stars

After the death of a massive, spinning star, a disk of material forms around the central black hole. As the material cools and falls into the black hole, new research suggests that detectable gravitational waves are created. Ore Gottlieb

The merging of black holes and neutron stars are among the most energetic events in the universe. Not only do they emit colossal amounts of energy, they can also be detected through gravitational waves. Observatories like LIGO/Virgo (Laser Interferometer Gravitational Wave Observatory) and KAGRA (The Kamioka Gravitational Wave Detector) have detected their gravitational waves but new gravitational wave observatories are now thought to be able to detect the collapse of a massive rapidly spinning star before it becomes a black hole. According to new research, collapsing stars within 50 million light years should be detectable.

August 29, 2024August 29, 2024 by Mark Thompson

Giant Low-Frequency Scan Searches for Aliens in 2,800 Galaxies

One of the tiles making up the 32T, a prototype instrument for the Murchison Widefield Array. Natasha Hurley-Walker

The search for extraterrestrial intelligence (SETI) has fascinated us for decades. Now a team of researchers have used the Murchison Widefield Array in Australia to scan great swathes of sky for alien signals. Unusually for a SETI project, this one focussed attention on 2,800 galaxies instead of stars within our own. They have been on the lookout for advanced civilisations that are broadcasting their existence using the power of an entire star. Alas they weren’t successful but its an exciting new way to search for alien intelligence.

August 28, 2024August 28, 2024 by Mark Thompson

Is Betelgeuse Actually a Binary Star?

This image, made with the Atacama Large Millimeter/submillimeter Array (ALMA), shows the red supergiant Betelgeuse — one of the largest stars known. In the millimeter continuum the star is around 1400 times larger than our Sun. The overlaid annotation shows how large the star is compared to the Solar System. Betelgeuse would engulf all four terrestrial planets — Mercury, Venus, Earth and Mars — and even the gas giant Jupiter. Only Saturn would be beyond its surface. Link Betelgeuse captured by ALMA Scientific paper

Betel-gurz or Beetle-juice has been a favourite among amateur astronomers for many years. However you pronounce it, its unexpected dimming draw even more attention to this red supergiant variable star in Orion. It has a few cycles of variability, one of them occurs over a 2,170 day period, 5 times longer than its normal pulsation period. A paper has just been published that suggests a companion star of 1.17 solar masses could be the cause. It would need an orbit about 2.43 times the radius of Betelgeuse and it might just lead to the modulation of dust in the region that causes the variations we see.

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 21, 2024August 21, 2024 by Mark Thompson

There Might Be Water on the Surface of the Metal Asteroid Psyche

An SwRI-led team used NASA’s Webb telescope, shown in the bottom right corner of this illustration, to confirm the presence of hydrated minerals on the surface of Psyche, a massive and heavily metallic body in the main asteroid belt. These findings suggest a complex history for this interesting asteroid, which many scientists think could be the remnant core of a protoplanet, including impacts with hydrated asteroids.

While a NASA probe heads for an asteroid known as Psyche, telescopes have been probing it to prepare for the arrival. Data from the James Webb Space Telescope has found something quite unexpected on the surface – hydrated molecules and maybe even water! The origin of the water is cause for much speculation, maybe it came from under the surface or from chemical interactions with the solar wind!

August 20, 2024August 20, 2024 by Mark Thompson

Citizen Scientists Find a Star Escaping the Milky Way

This artist's concept shows a hypothetical white dwarf, left, that has exploded as a supernova. The object at right is CWISE J1249, a star or brown dwarf ejected from this system as a result of the explosion. This scenario is one explanation for where CWISE J1249 came from. W.M. Keck Observatory/Adam Makarenko

Citizen science is such a great concept. Using the combined computing power of a gazillion (exaggeration) desktop and laptops to churn through data is an excellent and efficient way of analysing volumes of data. This has been shown yet again as a star has been identified to be hurtling out to intergalactic space! Most stars in the Milky Way are not travelling fast enough to be able to escape its immense gravity but the suspected brown dwarf is travelling at 1.5 million km/h, fast enough to escape.

August 13, 2024August 13, 2024 by Mark Thompson

Primordial Black Holes Could Kick Out Stars and Replace Them.

This artist's illustration shows what primordial black holes might look like. In reality, the black holes would struggle to form accretion disks, as shown. Image Credit: NASA’s Goddard Space Flight Center

Primordial black holes formed during the earliest stages of the evolution of the universe. Their immense gravity may be playing havoc in stellar systems. They can transfer energy into wide binary systems disrupting their orbits. Like celestial bullies their disruption might lead to extreme outcomes though like the ejection of a star, only to be replaced by the black hole itself! A new paper studies the interactions of systems like these and looks at ways we might be able to detect them.