Stellar Evolution Archives

August 18, 2023August 18, 2023 by Brian Koberlein

A New Simulation Reveals One Entire Stage of a Star's Life

The interior structure of our Sun. Credit: Kelvin Ma, via Wikipedia

Nuclear fusion is at the center of stellar evolution. Most of a star’s life is a battle between gravity and nuclear power. While we understand this process on a broad scale, many of the details still elude us. We can’t dive into a star to see its nuclear furnace, so we rely on complex computer simulations. A recent study has made a big step forward by modeling the entire fusion cycle of a single element.

August 4, 2023August 4, 2023 by Carolyn Collins Petersen

Yes! A JWST Image of the Ring Nebula

JWST/NIRcam composite image of the Ring Nebula. The images clearly show the main ring, surrounded by a faint halo and with many delicate structures. The interior of the ring is filled with hot gas. The star which ejected all this material is visible at the very center. Courtesy JWST/University of Manchester.

Brace yourselves for great JWST views of the iconic Ring Nebula (M57). An international team of astronomers just released a fantastic near-infrared image of the nebula, showing incredible details.

July 29, 2023July 29, 2023 by Carolyn Collins Petersen

Astronomers are Watching a Planet Get its Atmosphere Blasted Away into Space

This artist's illustration shows a planet (dark silhouette) passing in front of the red dwarf star AU Microscopii. The planet is so close to the eruptive star a ferocious blast of stellar wind and blistering ultraviolet radiation is heating the planet's hydrogen atmosphere, causing it to escape into space. The illustration is based on measurements made by the Hubble Space Telescope. Credits: NASA, ESA, and Joseph Olmsted (STScI)

What do you get when a hot young world orbits a wildly unstable young red dwarf? For AU Microsopii b, the answer is: flares from the star tearing away the atmosphere. That catastrophic loss happens in fits and starts, “hiccuping” out its atmosphere at one point and then losing practically none the next.

July 25, 2023July 25, 2023 by Brian Koberlein

Astronomers Have a New Trick to Work out the Age of Stars

A frame from the Kepler Telescope showing a couple binary systems. Credit: AIP/ David Gruner, NASA (Kepler FFI) & ESO (zoomed)

Twinkle, twinkle little star, I wonder just how old you are.

It isn’t an easy question to answer. Stars are notoriously difficult to age. We know the age of the Sun because we happen to live on one of its orbiting rocks, and we know very well how old the rock is. Without that information, things become a bit more fuzzy. But that could change thanks to a new study.

July 21, 2023July 21, 2023 by Carolyn Collins Petersen

Record-Breaking Magnetar was There in the Data All Along

An artist’s impression of the ultra-long period magnetar—a rare type of star with extremely strong magnetic fields that can produce powerful bursts of energy. Credit: ICRAR

The cosmic zoo has strange beasts that astronomers stumble across in the most fascinating ways. Not long ago a team in Australia found a highly unusual magnetar, one of the weirder denizens of the starry zoo. It’s called GPM J1839-10 and it lies some 15,000 light-years away in the direction of the constellation Scutum.

July 18, 2023July 18, 2023 by Nancy Atkinson

A Dying Red Giant Star has Thrown Out Giant Symmetrical Loops of Gas and Dust

A billowing pair of nearly symmetrical loops of dust and gas mark the death throes of an ancient red-giant star, as captured by the Gemini South telescope. Credit: International Gemini Observatory/NOIRLab/NSF/AURA

The Gemini South telescope has captured a new image of the glowing nebula IC 2220. Nicknamed the Toby Jug Nebula, this object got its name because it looks like an old English jug. But no fun drinking games are happening here.

June 25, 2023June 25, 2023 by Carolyn Collins Petersen

Supervillains Take Note. Here’s a New Way to Destroy a Star

Astronomers studying a powerful gamma-ray burst (GRB) with the International Gemini Observatory may have observed a never-before-seen way to destroy a star. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick/M. Zamani

If you’re an evil genius supervillain looking to freak out your enemy with a big messy space kablooie, here’s a novel way to do it. Smack a couple of ancient star remnants together right in front of your nemesis. The result will give you a gratifyingly huge, bright explosion plus a bonus gamma-ray burst visible across the Universe. And, it’ll scare everybody into doing your evil bidding.

June 20, 2023June 20, 2023 by Carolyn Collins Petersen

Astronomers Find a White Dwarf Pulsar

An artist's conception of a white dwarf pulsar pair. Two are now known. Credit: University of Warwick.

When astronomers talk about the “end states” of stellar evolution, several categories come to mind: black holes, neutron stars/pulsars, and white dwarfs. What happens if one star ends up in two of these states? That’s the case with a genre-breaking white dwarf pulsar called J191213.72-441045.1 (J1912-4410 for short). It’s part of a binary pair that includes a red dwarf star.

June 14, 2023June 14, 2023 by Evan Gough

A White Dwarf is Starting to Crystallize into Diamond

An artist’s impression of crystallization in a white dwarf star. The twho known white dwarf pulsars may have interiors like this. Image credit: Mark Garlick / University of Warwick.

White dwarfs are the stellar remnants of stars like our Sun. They’re strange objects, and astrophysicists think their cores can crystallize into enormous diamonds. But they need to find more of these strange objects, and they need to know their ages, to understand how and when it happens.

May 16, 2023May 12, 2023 by Paul M. Sutter

Astronomers Find a “Red Nova”: A Main-Sequence Star Just Eating its Planet

Artist's impression of a Jupiter-sized exoplanet orbiting an M-dwarf star

Back in 2020 astronomers observed a Red Nova, which while enormously powerful, is on the low side of energetic events in the universe. Now an astronomer has studied the event in close detail and has come to the conclusion that we have just witnessed a star destroying its own planet.