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.

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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.

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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.

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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.

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Some Elements Arrived on Earth by Surfing Supernova Shock Waves

Neutron-neutron star mergers are one way that heavy radioactive isotopes of elements found on Earth could be created. Courtesy ESO.
Neutron-neutron star mergers are one way that heavy radioactive isotopes of elements found on Earth could be created. Courtesy ESO.

When stars die, they spread the elements they’ve created in their cores out to space. But, other objects and processes in space also create elements. Eventually, that “star stuff” scatters across the galaxy in giant debris clouds. Later on—sometimes millions of years later—it settles onto planets. What’s the missing link between element creation and deposition on some distant world?

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Astronomers Spot Three Interacting Systems with Twin Discs

Artist's conceptualization of the dusty TYC 8241 2652 system as it might have appeared several years ago when it was emitting large amounts of excess infrared radiation. Credit: Gemini Observatory/AURA artwork by Lynette Cook. https://www.gemini.edu/node/11836

According to the most widely-accepted theory about star formation (Nebular Hypothesis), stars and planets form from huge clouds of dust and gas. These clouds undergo gravitational collapse at their center, leading to the birth of new stars, while the rest of the material forms disks around it. Over time, these disks become ring structures that accrete to form systems of planets, planetoids, asteroid belts, and Kuiper belts. For some time, astronomers have questioned how interactions between early stellar environments may affect their formation and evolution.

For instance, it has been theorized that gravitational interactions with a passing star or shock waves from a supernova might have triggered the core collapse that led to our Sun. To investigate this possibility, an international team of astronomers observed three interacting twin disc systems using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the ESO’s Very Large Telescope (VLT). Their findings show that due to their dense stellar environments, gravitational encounters between early-stage star systems play a significant role in their evolution.

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The Latest JWST Image Shows a Star in the Earliest Stage of Formation

The NASA/ESA/CSA James Webb Space Telescope has revealed the once-hidden features of the protostar within the dark cloud L1527 with its Near Infrared Camera (NIRCam), providing insight into the formation of a new star. These blazing clouds within the Taurus star-forming region are only visible in infrared light, making it an ideal target for Webb. Image Credit: NASA, ESA, CSA, and STScI, J. DePasquale (STScI), CC BY-SA 3.0 IGO

What’s the most exciting thing about the James Webb Space Telescope? The stunning images? The completion of its torturous path from concept to launch?

Or is it because it provides such compelling visual evidence of objects and processes long theorized about but difficult to observe?

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Hubble saw the Same Supernova at Three Different Times Thanks to Gravitational Lensing

supernova explosion
The Crab Nebula; at its core is a long dead star. Did early massive stars die in supernova explosions like this? Image credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)

As cosmic events go, supernova explosions epitomize the saying, “Live fast, die young, and leave a good-looking corpse.” They’re the deaths of stars so massive that they tear through their fuel in a short time. Then, they explode and create gorgeous scenes of stellar destruction. These seminal events enrich the universe with chemical elements for new generations of stars and planets.

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