Brian Koberlein, Author at Universe Today

July 30, 2022July 30, 2022 by Brian Koberlein

When Stars eat Their Planets, the Carnage can be Seen Billions of Years Later

Artist view of a large planet soon to be devoured by its star. Credit: NASA, ESA, and G. Bacon (STScI). Science Credit: NASA, ESA, and C. Haswell (The Open University, UK)

The vast majority of stars have planets. We know that from observations of exoplanetary systems. We also know some stars don’t have planets, and perhaps they never had planets. This raises an interesting question. Suppose we see an old star that has no planets. How do we know if ever did? Maybe the star lost its planets during a close approach by another star, or maybe the planets spiraled inward and were consumed like Chronos eating his children. How could we possibly tell? A recent study on the arXiv answers half that question.

July 28, 2022July 28, 2022 by Brian Koberlein

A Fast-Moving Star is Colliding With Interstellar gas, Creating a Spectacular bow Shock

A multi-wavelength view of Zeta Ophiuchi. Credit: X-ray: NASA/CXC/Dublin Inst. Advanced Studies/S. Green et al.; Infrared: NASA/JPL/Spitzer

Zeta Ophiuchi has had an interesting life. It began as a typical large star about twenty times more massive than the Sun. It spent its days happily orbiting a large companion star until its companion exploded as a supernova about a million years ago. The explosion ejected Zeta Ophiuchi, so now it is speeding away through interstellar space. Of course, the supernova also expelled the outer layers of the companion star, so rather than empty space, our plucky star is speeding through the remnant gas as well. As they say on Facebook, it’s complicated. And that’s great news for astronomers, as a recent study shows.

July 23, 2022July 23, 2022 by Brian Koberlein

Gamma-ray Bursts can Help Astronomers Measure Vast Distances Across the Universe

An illustration of a powerful gamma ray burst. Credit: NAOJ

Now that the James Webb Space Telescope is operational, astronomers can study some of the most faint and distant galaxies ever seen. By some accounts, we may have already captured the image of a galaxy from when the universe was just 300 million years old. But we can’t be entirely sure of its distance, and that is a big problem for astronomers.

July 8, 2022July 8, 2022 by Brian Koberlein

Supermassive Black Holes Formed Directly out of Enormous Streams of Cold gas

Artist impression of a powerful young quasar. Credit: ESO/M. Kornmesser Credit: ESO/M. Kornmesser

At the edge of known space are quasars. They are powerful cosmic engines capable of creating intense beams of light across billions of light years. And they are powered by supermassive black holes (SMBHs). Most galaxies have a SMBH, including our own galaxy, but for quasars to be so powerful their SMBHs must have become very large very quickly. We’re still learning just how they formed. We’ve long thought their formation involved a special set of circumstances, but a new study shows that early quasars could have formed purely from cold dark gas.

June 24, 2022June 24, 2022 by Brian Koberlein

Astronomers Find a Brand new Pulsar That's Probably Less Than 14 Years old

Artist view of the neutron star VT 1137-0337. Credit: Melissa Weiss, NRAO/AUI/NSF

Neutron stars are dense remnants of large stars. They are the collapsed cores of stars formed during a supernova explosion. While we know generally how they form, we are still learning how they evolve, particularly when they are young. But that’s starting to change thanks to large sky surveys, which have allowed astronomers to observe a neutron star that could be little more than a decade old.

June 22, 2022June 22, 2022 by Brian Koberlein

Another few Weeks of Observations Could Tell us if the Wow! Signal Repeats

A new study from the Center for Planetary Science claims that a comet may be responsible fr the famous Wow! Signal. Credit: NASA/JPL-Caltech

In the decades-long search for extraterrestrial intelligence, there has never been confirmed evidence of an alien signal. There have, however, been a few tantalizing mysteries. Perhaps the greatest of these is known as the Wow Signal.

June 5, 2022June 5, 2022 by Brian Koberlein

Does a “Mirror World of Particles” Explain the Crisis in Cosmology?

Why create one universe when you could create two? Credit: NASA/WMAP Science Team, modified by Brian Koberlein

The idea of a mirror universe is a common trope in science fiction. A world similar to ours where we might find our evil doppelganger or a version of us who actually asked out our high school crush. But the concept of a mirror universe has been often studied in theoretical cosmology, and as a new study shows, it might help us solve problems with the cosmological constant.

May 15, 2022May 15, 2022 by Brian Koberlein

A Recently Discovered Double Binary System is Unstable. Stars Could Collide, Leading to a Supernova

Artist view of an orbiting binary star. Credit: ESO/L. Calçada

Multiple star systems are very common in the Milky Way. While most of these systems are binary systems consisting of two stars, others contain three, four, or even six stars. These systems tend to be pretty stable since unstable systems tend to break apart or merge fairly quickly, but sometimes you can get a kind of meta-stable system. One that lasts long enough for stars to evolve while still being stable in the end. And that end could be a supernova.

May 8, 2022May 8, 2022 by Brian Koberlein

A Supermassive Black Hole Just Flipped its Entire Magnetic Field

Artist illustration of the supermassive black hole in 1ES 1927+654 before the flare. Credit: NASA/Sonoma State University, Aurore Simonnet

Black holes are powerful cosmic engines. They provide the energy behind quasars and other active galactic nuclei (AGNs). This is due to the interaction of matter with its powerful gravitational and magnetic fields.

Technically, a black hole doesn’t have a magnetic field on its own, but the dense plasma surrounding the black hole as an accretion disk does. As the plasma swirls around the black hole, the charged particles within it generate an electrical current and magnetic field. The direction of the plasma flow doesn’t change spontaneously, so one would imagine the magnetic field is very stable. So imagine the surprise of astronomers when they saw evidence that a black hole’s magnetic field had undergone a magnetic reversal.

April 21, 2022April 21, 2022 by Brian Koberlein

Venus' Atmosphere Stops it From Locking to the Sun

Of the thousands of exoplanets we’ve discovered, most of them closely orbit red dwarf stars. Part of this is because planets with short orbital periods are easier to find, but part of this is that red dwarf stars make up about 75% of the stars in our galaxy. This propensity of close orbiting planets has some pretty big implications for “potentially habitable” worlds, not the least of which is that most of these planets are likely tidally locked to their star. Or so we’ve thought.