Stellar Evolution Archives

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.

May 3, 2023May 3, 2023 by Carolyn Collins Petersen

Astronomers are Starting to Find the Wreckage Left Over from the First Stars in the Universe

Using ESO’s Very Large Telescope (VLT), researchers have found for the first time the fingerprints left by the explosion of the first stars in the Universe. They detected three distant gas clouds whose chemical composition matches what we expect from the first stellar explosions. These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang. — This artist’s impression shows a distant gas cloud that contains different chemical elements, illustrated here with schematic representations of various atoms. Using ESO’s Very Large Telescope, astronomers have detected three distant gas clouds whose chemical composition matches what we expect from the explosions of the first stars that appeared in the Universe. These early stars can be studied indirectly by analysing the chemical elements they dispersed into the surrounding environment after they died in supernova explosions. The three distant gas clouds detected in this study are rich in carbon, oxygen, and magnesium, but poor in iron. This is exactly the signature expected from the explosions of the first stars.

The first stars were odd ducks. Nobody’s observed them yet (although astronomers are hopeful JWST might spot them someday) but their ghosts remain. Born more than 13.5 billion years ago, they were very different from most of those we know today. These were massive monsters made mostly of hydrogen and helium. And, when they exploded as supernovae, their “starstuff” got scattered to space. Astronomers have now found the chemical remains of those stars in three distant gas clouds observed by European Southern Observatory’s Very Large Telescope.

March 23, 2023March 23, 2023 by Evan Gough

The Discovery of a Hot Neptune that Shouldn’t Exist

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

1800 light-years away, an unlikely survivor orbits an aged star. This rare planet is called a hot Neptune, and it’s one of only a small handful of hot Neptunes astronomers have found. Hot Neptunes are so close to their stars that the overpowering stellar radiation should’ve stripped away their atmospheres, leaving only a planetary core behind.

But this planet held onto its atmosphere somehow.

March 21, 2023March 21, 2023 by Carolyn Collins Petersen

JWST Sees Organic Molecules Swirling Around a Newborn Star

A newborn star in the Lupus 1 Molecular cloud is showing complex organic molecules that could be life precursors. The Webb space telescope is studying this cloud to find these chemicals. Courtesy Gabriel Rodrigues Santos. From https://science.nasa.gov/barnard-228-dark-wolf-nebula-lupus — A newborn star in the Lupus 1 Molecular cloud is showing that complex organic molecules exist it its birth cloud. They could be life precursors. The Webb space telescope is studying this cloud to find these chemicals. Courtesy Gabriel Rodrigues Santos. From https://science.nasa.gov/barnard-228-dark-wolf-nebula-lupus

One of the most interesting questions we can ask is, “How did life form?”. To answer it, scientists go back to look at the basic chemical building blocks of life. Those are water, carbon-based organic molecules, silicates, and others. The James Webb Space Telescope offered a peek at the gases, ice particles, and dust surrounding a newborn star and found organic molecules exist there.