Brian Koberlein, Author at Universe Today

December 14, 2021December 14, 2021 by Brian Koberlein

Forget That Planet That Orbits Every 16 Hours. That’s so Last Week. Now Astronomers Have Found a Metal Planet That Orbits its Star EVERY 8 HOURS

Artist view of a hot planet orbiting a red dwarf star. Credit: Patricia Klein

Most exoplanets are found using a technique known as the transit method, where the exoplanet passes in front of its star, causing the star to dim slightly. It takes several transits to confirm an exoplanet, so it’s not surprising that most known exoplanets have a fairly short orbital period. Months or days rather than years. There’s also an observational bias in that most known stars are red dwarfs, so it’s usually not surprising that we’ve found yet another exoplanet closely orbiting a red dwarf star. But sometimes what we find is so extreme, it really is surprising.

December 6, 2021December 6, 2021 by Brian Koberlein

Maybe “Boson Clouds” Could Explain Dark Matter

Coalsack Nebula and Kappa Crucis Cluster, photo: A. Fujii — The Jewel Box is shown just right of center, above the dark nebula called the Coal Sack in this picture of the southern sky. The picture was taken with a small ground-based camera.

The nature of dark matter continues to perplex astronomers. As the search for dark matter particles continues to turn up nothing, it’s tempting to throw out the dark matter model altogether, but indirect evidence for the stuff continues to be strong. So what is it? One team has an idea, and they’ve published the results of their first search.

November 27, 2021November 27, 2021 by Brian Koberlein

Stars Getting Kicked out of the Milky Way can Help us map its Dark Matter Halo

Artist concept showing a hypervelocity star escaping our galaxy. Credit: NASA, ESA, and G. Bacon (STScI)

Dark matter is notoriously difficult to study. It’s essentially invisible to astronomers since it can’t be seen directly. So astronomers rely on effects such as the gravitational lensing of light to map its presence in the universe. That method works well for other galaxies, but not so well for our own. To map dark matter in the Milky Way, we rely mostly on the motions of stars in our galaxy. Since dark matter attracts regular matter gravitationally, the method works well for areas of the galaxy where there are stars. Unfortunately, most of the stars lie along the galactic plane, making it difficult to map dark matter above and below that plane. But a recent study proposes a way to map more of our galaxy’s dark matter using runaway stars.

November 19, 2021November 19, 2021 by Brian Koberlein

An Absolutely Bonkers Plan to Give Mars an Artificial Magnetosphere

A scientific visualization of the electromagnetic currents around Mars. Credit: NASA/Goddard/MAVEN/CU Boulder/SVS/Cindy Starr

Terraforming Mars is one of the great dreams of humanity. Mars has a lot going for it. Its day is about the same length as Earth’s, it has plenty of frozen water just under its surface, and it likely could be given a reasonably breathable atmosphere in time. But one of the things it lacks is a strong magnetic field. So if we want to make Mars a second Earth, we’ll have to give it an artificial one.

November 12, 2021November 12, 2021 by Brian Koberlein

Understanding the Early Universe Depends on Estimating the Lifespan of Neutrons

How NASA's Lunar Prospector could study neutron decay. Credit: Johns Hopkins APL/Ben Smith

When we look into the night sky, we see the universe as it once was. We know that in the past the universe was once warmer and denser than it is now. When we look deep enough into the sky, we see the microwave remnant of the big bang known as the cosmic microwave background. That marks the limit of what we can see. It marks the extent of the observable universe from our vantage point.

November 5, 2021November 5, 2021 by Brian Koberlein

Experiment Finds no Sign of Sterile Neutrinos

Could sterile neutrinos be a fourth kind of neutrino? Credit: IceCube - University of Wisconsin

We don’t know what dark matter is. We do know the characteristics of dark matter, and much of how it behaves, so we know what physical properties dark matter must have, but no known matter has all the necessary characteristics of dark matter. So we’re stumped.

November 2, 2021November 2, 2021 by Brian Koberlein

Moons are Planets too

Moons of the solar system compared to Earth. Credit: NASA

What makes a planet a planet? The answer turns out to be rather contentious. The official definition of a planet, as defined by the International Astronomical Union (IAU) is that a planet must satisfy three conditions:

It must orbit the Sun.
It must be in hydrostatic equilibrium.
It must have cleared its orbital neighborhood.

By this definition there are just eight planets in our solar system, most notably excluding Pluto. This has stirred all manner of controversy, even among astronomers. Several alternative definitions have been proposed, but a new study argues we should look to history for the solution.

October 23, 2021October 27, 2021 by Brian Koberlein

Primordial Gravitational Waves Continue to Elude Astronomers

The BICEP telescope in Antarctica during twilight. Credit: Steffen Richter, Harvard University

The standard model of cosmology is a remarkably powerful and accurate description of the universe, tracing its evolution from the big bang to its current state, but it is not without mysteries. One of the biggest unsolved questions of the standard model is known as early cosmic inflation.

October 3, 2021October 4, 2021 by Brian Koberlein

Future Telescopes Could be Seeing the Wrong Planets

NASA’s Wide Field Infrared Survey Telescope (WFIRST) is now named the Nancy Grace Roman Space Telescope, after NASA’s first Chief of Astronomy. Credits: NASA

We have discovered thousands of exoplanets in recent years, including some that are Earth-sized and potentially habitable. But we haven’t seen many of those worlds. Most of the exoplanets we’ve found have been discovered using the transit method, which involves watching the brightness of a star dip as a planet passes in front of it. We can learn the size and sometimes the mass from these dips, but we have no idea what the world looks like, or whether it has a breathable atmosphere.

September 29, 2021September 29, 2021 by Brian Koberlein

Aging White Dwarfs Become Even More Magnetic

An artist view of a highly magnetized neutron star -- a magnetar. It's thought that these objects have solid surfaces and suffer eruptions when their magnetic fields are disturbed. Credit: Carl Knox/ OzGrav

In a few billion years the Sun will end its life as a white dwarf. As the Sun runs out of hydrogen to fuse for energy it will collapse under its own weight. Gravity will compress the Sun until it’s roughly the size of Earth, at which point a bit of quantum physics will kick in. Electrons from the Sun’s atoms will push back against gravity, creating what is known as degeneracy pressure. Once a star reaches this state it will cool over time, and the once brilliant star will eventually fade into the dark.