Brian Koberlein, Author at Universe Today

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.

September 6, 2023September 6, 2023 by Brian Koberlein

Humanity Will Out-Communicate all Life on Earth Within 90 Years

A male Japanese Bush Warbler singing. Credit: Wikipedia user Alpsdake (CC BY-SA 3.0)

Life on Earth is a glorious dance of data. From the songs of backyard birds to the chemical exchanges of forest trees, the exchange of information between living things is an essential part of its existence and evolution. Humans, too, are a part of that dance, with friendship chats over morning coffee, bold headlines in newspapers, and TikTok videos of teenagers. Right now human data is just one part of Earth’s living data exchange, but it could soon become the overwhelming dominant part. If the same is true for all advanced civilizations, it could impact our search for alien life.

September 5, 2023September 5, 2023 by Brian Koberlein

A New Telescope Could Detect Decaying Dark Matter in the Early Universe

The Hydrogen Epoch of Reionization Array (HERA). Credit: HERA Collaboration

Hydrogen is the most abundant element in the Universe. By far. More than 90% of the atoms in the Universe are hydrogen. Ten times the number of helium atoms, and a hundred times more than all other elements combined. It’s everywhere, from the water in our oceans to the earliest regions of the Cosmic Dawn. Fortunately for astronomers, all this neutral hydrogen can emit a faint emission line of radio light.

September 4, 2023September 4, 2023 by Brian Koberlein

It's Going to Take More Than Early Dark Energy to Resolve the Hubble Tension

Artist impression of a cluster of galaxies in the early Universe. Credit: S. Dagnello; NSF/NRAO/AUI

Our best understanding of the Universe is rooted in a cosmological model known as LCDM. The CDM stands for Cold Dark Matter, where most of the matter in the universe isn’t stars and planets, but a strange form of matter that is dark and nearly invisible. The L, or Lambda, represents dark energy. It is the symbol used in the equations of general relativity to describe the Hubble parameter, or the rate of cosmic expansion. Although the LCDM model matches our observations incredibly well, it isn’t perfect. And the more data we gather on the early Universe, the less perfect it seems to be.

September 3, 2023September 3, 2023 by Brian Koberlein

The Closest Supernova Seen in the Modern Era, Examined by JWST

SN 1987a as seen by JWST's Near-Infrared Camera. Credit: NASA, ESA, CSA, M. Matsuura, R. Arendt, C. Fransson

In November of 1572, Tycho Brahe noticed a new star in the constellation Cassiopeia. It was the first supernova to be observed in detail by Western astronomers and became known as Tycho’s Supernova. Earlier supernovae had been observed by Chinese and Japanese astronomers, but Tycho’s observations demonstrated to the Catholic world that the stars were not constant and unchanging as Aristotle presumed. Just three decades later, in 1604, Johannes Kepler watched a supernova in the constellation Ophiuchus brighten and fade. There have been no observed supernovae in the Milky Way since then.

September 2, 2023September 2, 2023 by Brian Koberlein

Astronomers are Hoping the Event Horizon Telescope saw Pulsars Near the Milky Way's Supermassive Black Hole

Visualization of a fast-rotating pulsar. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

Millisecond pulsars are amazing astronomical tools. They are fast-rotating neutron stars that sweep beams of radio energy from their magnetic poles, and when they are aligned just right we see them as rapidly flashing radio beacons. They flash with such regularity that we can treat them as cosmic clocks. Any change in their motion can be measured with extreme precision. Astronomers have used millisecond pulsars to measure their orbital decay due to gravitational waves and to observe the background gravitational rumblings of the universe. They have even been proposed as a method of celestial navigation. They may soon also be able to test the most fundamental nature of gravity.

September 1, 2023September 1, 2023 by Brian Koberlein

If Earth Was an Exoplanet, JWST Would Know There's an Intelligent Civilization Here

Sunrise over the Gulf of Saint Lawrence. Credit: NASA's Earth Observatory

Yesterday I presented a rather pessimistic view about our chances of finding evidence of alien civilizations. That work focused on detecting physical structures on an alien planet, which would take an optical telescope array the size of Saturn’s orbit. Today I’ll talk about a more optimistic view, one which focuses not on physical structures, but the fingerprint of molecules in an alien atmosphere. It’s a task that is not only much easier, it’s something we could do now using the James Webb Space Telescope (JWST).

August 31, 2023August 31, 2023 by Brian Koberlein

Do Advanced Civilizations Know We're Here?

Antennas of the Very Large Array against the Milky Way. Credit: NRAO/AUI/NSF/Jeff Hellerman

Adrift in a great sea of stars, we must surely not be alone.

It’s hard not to look at the night sky and think about the possibility of other civilizations out there. From the philosophical speculations of Giordano Bruno to the statistical estimations of Frank Drake, the more we’ve learned about the universe, the more likely alien life seems to be. And yet, in our search for this life, we have heard nothing but silence.

August 30, 2023August 30, 2023 by Brian Koberlein

It's Time for a Gravitational Wave Observatory in the Southern Hemisphere

Map of current and planned gravitational wave observatories. Credit: Caltech/MIT/LIGO Lab

What’s true for optical astronomy is also true for gravitational wave astronomy: the more observatories you have, the better your view of the sky. This is why the list of active gravitational wave observatories is growing. But so far they are all in the Northern Hemisphere. As a recent article on the arXiv points out, that means we are missing out on a good number of gravitational events.

August 29, 2023August 29, 2023 by Brian Koberlein

Astronomers Precisely Measure a Black Hole's Accretion Disk

How astronomers can measure the width of an accretion disk. Credit: NOIRLab/NSF/AURA/P. Marenfeld

When you think of a black hole, you might think its defining feature is its event horizon. That point of no return not even light can escape. While it’s true that all black holes have an event horizon, a more critical feature is the disk of hot gas and dust circling it, known as the accretion disk. And a team of astronomers have made the first direct measure of one.