Brian Koberlein, Author at Universe Today

September 17, 2023September 17, 2023 by Brian Koberlein

A New Observatory Will Spot Core-Collapse Supernovae Before They Explode

Jiangmen Underground Neutrino Observatory (JUNO) under construction. Credit: CGTN

The thing about a supernova is that you never know when it might occur. Supernovae are triggered either by a collision with another star or when the interior of a massive star becomes depleted of nuclear fuel and begins a rapid collapse. Neither of these show any major optical changes before the explosion, so we are left to scan the sky in the hopes of catching one in its early stages. But that could soon change.

September 15, 2023September 15, 2023 by Brian Koberlein

A 2022 Gamma Ray Burst Was So Powerful, it was Detected by Spacecraft Across the Solar System

Artist's depiction of a powerful gamma ray burst. Credit: NASA, ESA and M. Kornmesser

On October 9, 2022, a gamma-ray burst illuminated the solar system. Its light had traveled 2.4 billion years to reach us, having begun its journey when only bacteria and archaea existed on the Earth and oxygen was not yet plentiful in our air. Despite its long journey, the flash of light was tremendously bright.

September 14, 2023September 14, 2023 by Brian Koberlein

If Neutron Stars Have Mountains, They Should Generate Gravitational Waves

Artist's depiction of a highly magnetize neutron star known as a magnetar. Credit: NASA's Goddard Space Flight Center/S. Wiessinger

A neutron star is 2 solar masses compressed into a ball only 12 kilometers wide. Its surface gravity is so immense it compresses atoms and molecules into raw nuclei and squeezes electrons into protons transforming them into neutrons. Given such immense pressures and densities, you might assume neutron stars have an almost perfectly smooth surface. But you’d be wrong because we know that neutron stars can have mountains.

September 13, 2023September 13, 2023 by Brian Koberlein

Has the First Biosignature Been Found on an Exoplanet?

Artist's impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity. Credit: Oleg Kuznetsov — Artist's impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity, and distant exoplanets might begin similarly. Credit: Oleg Kuznetsov

Recently I wrote about the discovery of a hycean world. A potentially habitable exoplanet with a deep warm ocean and thick, hydrogen-rich atmosphere. Such planets are thought to be somewhat common orbiting red dwarf stars, and they are an excellent candidate for life. While it’s an exciting discovery, buried in the research article was something even more exciting. Tentative evidence of a biosignature, hinting at the presence of life. You can guess which discovery started making headlines. But have astronomers really found life on another planet?

September 12, 2023September 12, 2023 by Brian Koberlein

Do The Gaps in Protoplanetary Disks Really Indicate Newly Forming Planets?

Artist depiction of a protoplanetary disk in which planets are forming. Credit: ESO/L. Calçada

Roughly 5 billion years ago Earth was in the process of forming. Gas and dust gathered with the young Sun’s protoplanetary disk, likely nudged a bit by the resonant gravitational pull of Jupiter and other large worlds. One can imagine that as Earth formed it swept its orbit clear of debris, leaving a gap in the disk visible from light years away. While we know this tale is reasonably accurate, the idea that planets such as Earth always clear gaps in a protoplanetary disk likely isn’t.

September 11, 2023September 11, 2023 by Brian Koberlein

JWST Might Have Imaged a Hycean World for the First Time, With a Hydrogen-Rich Atmosphere and a Deep Planet-Wide Water Ocean

Artist depiction of the mini-Neptune K2-18 b. Credit: NASA, CSA, ESA, J. Olmstead (STScI), N. Madhusudhan (Cambridge University)

Despite its great oceans, Earth is not really an ocean world. It has less water than icy moons such as Europa and Enceladus, a relatively thin nitrogen-rich atmosphere, and vast continents that rise above sea level. A true ocean world would have no continents, a warm sea hundreds of kilometers deep, and a thick hydrogen and water-rich atmosphere. They are known as hydrogen-ocean planets or hycean worlds. While we’ve long thought they exist, the James Webb Space Telescope may now have found one.

September 10, 2023September 10, 2023 by Brian Koberlein

The Closest Black Holes to Earth are Probably Hidden in This Nearby Star Cluster

The Hyades cluster, which is the closest star cluster to Earth. Credit: NASA, ESA, and STScI

In the constellation Taurus, there is a cluster of a few hundred stars known as the Hyades. The cluster is just 150 light-years away, and it could be harboring a stellar-mass black hole.

September 9, 2023September 9, 2023 by Brian Koberlein

The Case for a Small Universe

A logarithmic view of the Universe. Credit: Pablo Carlos Budassi

The Universe is big, as Douglas Adams would say.

The most distant light we can see is the cosmic microwave background (CMB), which has taken more than 13 billion years to reach us. This marks the edge of the observable universe, and while you might think that means the Universe is 26 billion light-years across, thanks to cosmic expansion it is now closer to 46 billion light-years across. By any measure, this is pretty darn big. But most cosmologists think the Universe is much larger than our observable corner of it. That what we can see is a small part of an unimaginably vast, if not infinite creation. However, a new paper argues that the observable universe is mostly all there is.

In other words, on a cosmic scale, the Universe is quite small.

September 8, 2023September 8, 2023 by Brian Koberlein

Should the Next Big Observatories Be Built on the Moon?

Concept of a radio telescope in a lunar crater. Credit: Vladimir Vustyansky

We have built telescopes in our backyards, and high upon remote mountains, and even launched telescopes into space. With each advancement in our technology, we have made amazing and surprising new discoveries about the Universe. So what should our next advance in observatories be? Based on a new paper on the arXiv, a good choice would be the lunar surface.

September 7, 2023September 7, 2023 by Brian Koberlein

The Most Distant Galactic Field Lines Ever Seen

Mapping of the magnetic field in the distant 9io9 galaxy. Credit: ALMA (ESO/NAOJ/NRAO)/J. Geach et al.

The galaxies in our local Universe all have magnetic fields. Galactic magnetic fields can be generated by ionized gas within a galaxy, and these same magnetic fields affect the evolution of galaxies. But while modern galaxies have magnetic fields, did early ones? Astronomers are still trying to understand how galactic magnetic fields arise in young galaxies, but this can be a challenge without observational data. Now a team using data from the Atacama Large Millimeter/submillimeter Array (ALMA) has observed the magnetic field of a galaxy when the Universe was just 2.5 billion years old. The galaxy is known as 9io9. It takes 11 billion years for its light to reach us, making it the most distant galaxy for which we have observed a magnetic field.