Stellar Evolution

Stellar Evolution

Two side-by-side images of a galaxy cluster in space, captured by JWST, showcase numerous bright galaxies and stars on a dark background—highlighting one of the most extreme gravitational lens effects ever observed.
Massive galaxy cluster Abell S1063, 4.5 billion light-years away, bends and distorts the space nearby. Here's what a JWST deep field shows.
Image of two large elliptical galaxies surrounded by several smaller, colorful galaxies and stars against a dark background in space.
The first galaxies were irregular blobs of gas and stars. But modern features, like spiral arms and bars, appeared earlier than expected.
An artist's impression of a cluster of stars.
If the Universe is 13.8 billion years old today, but different ages the farther we look back, what does it mean for a star to be the first?
An artist's impression of a cluster of stars.
Many were hoping that JWST would find the first stars of all. Despite many hopeful claims, it hasn't, and probably can't. Here's how we can.
heavy neutral atom
If it weren't for the intricate rules of quantum physics, we wouldn't have formed neutral atoms "only" ~380,000 years after the Big Bang.
Two bright, irregularly shaped nebula clouds with blue, purple, and pink gases dominate the dark space background, where dazzling stars twinkle—reminding us that in space, appearances can deceive.
There's an old saying that "what you see is what you get." When it comes to the Universe, however, there's often more to the full story.
Bright star at the center of a blue nebula radiates mass energy, surrounded by numerous smaller stars, with diffraction spikes visible from the brightest stars.
All stars shine due to an internal source of energy. Usually, it's nuclear fusion: converting mass into energy. What makes them most bright?
Photons come in every wavelength you can imagine. But one particular quantum transition makes light at precisely 21 cm, and it's magical.
planetary nebulae
In around 7 billion years, we expect the Sun to run out of fuel, dying in a planetary nebula/white dwarf combination. Is that for certain?
A glowing orange planet casts a shadow in space amid a backdrop of stars.
Exoplanets can exist anywhere around their parent stars, even so close that they evaporate or disintegrate. Even the rocky ones.
We understand many things about our Universe, and our home within it, extremely well. The number of stars in the Milky Way isn't among them.
globular cluster terzan 5
For centuries, even after we knew the Sun was a star like any other, we still didn't know what it was made of. Cecilia Payne changed that.
Colorful galaxy with dark dust lanes and bright stars, set against a deep space background.
Someday, we'll look back and see a young galaxy forming stars for the first time. JADES-GS-z14-0, the farthest ever, isn't early enough.
A grid of six Hubble Space Telescope images showcases different types of colorful nebulae with intricate shapes against a starry backdrop.
Some nebulae emit their own light, some reflect the light from stars around them, and some only absorb light. But that's just the beginning.
A tilted spiral galaxy gracefully tipped towards the viewer reveals a bright core and dark, dusty rings, set against the infinity of deep blue space.
When we see spiral galaxies, some are face-on, others are edge-on, but most are tipped at an angle. But which side is closest to us?
A red star is at the center, with five orbiting paths marked by yellow dots, resembling exoplanets around the nearest single star, set against a starry night backdrop that illustrates a planetary system.
Barnard's star, the closest singlet star system to ours, has long been a target for planet-hunters. We've finally confirmed it: they exist!
A galaxy with bright stars and swirling clouds of dust creates the largest galactic mosaic, set against a dark space backdrop.
The full extent of the Andromeda galaxy, the nearest large galaxy to our own, has been entirely imaged with Hubble's exquisite cameras.
Astronomical image of a young star system with labeled features: jet, conical outflow, dark lane, possible spiral, disk, tail, and a scale marking 300 astronomical units.
A young, nearby, massive star, whose protoplanetary disk appears perfectly edge-on, was just viewed by JWST, with staggering implications.
warm-hot intergalactic medium sculptor wall
Here in our Universe, both normal and dark matter can be measured astrophysically. But only normal matter can collapse. Why is that?
elements
From LIGO, there weren't enough neutron star-neutron star mergers to account for our heavy elements. With a JWST surprise, maybe they can.
A dark nebula with dimming T Tauri stars nestled among dust and gas. The nebula casts a shadowy silhouette against a backdrop of numerous smaller stars in space.
It's the ultimate game of cosmic "cover up," as the dimming occurs when a circumbinary disk from a nearby star passes in front of T Tauri North.
Illustration of the periodic table with a human silhouette reveals how heaviest elements shape us. Elements are color-coded, depicting the percentage composition of the body: 73% oxygen, 16.5% carbon, 9.5% hydrogen, and 1% others.
Matter is made up largely of atoms, where atomic nuclei can contain up to 100 protons or more. But how were the heaviest elements made?
A dense star field with various galaxies and cosmic bodies scattered, showcasing a vibrant and colorful view of space. Among them, an isolated galaxy grows in brilliance, capturing the imagination with its distant allure.
Scientists just viewed one of the tiniest, most isolated, lowest-mass galaxies ever found with JWST. Despite all odds, it's still growing.
Three images of the Ring Nebula reveal its true shape: visible light (left), infrared (center), and a composite with contour lines (right) showcasing different details of the nebula's intricate structure.
The Ring Nebula, a bright, circular planetary nebula, is created by a dying Sun-like star. After centuries, we finally know its true shape.
A bright star emits light in a field of smaller, scattered stars against a dark sky.
Most stars shine with properties, like brightness, that barely change at all with time. The ones that do vary help us unlock the Universe.
There's no upper limit to how massive galaxies or black holes can be, but the most massive known star is only ~260 solar masses. Here's why.
Sunlight, like a quantum sun, streams through tree branches, casting golden rays over a calm lake.
Despite the Sun's high core temperatures, atomic nuclei repel each other too strongly to fuse together. Good thing for quantum physics!
In the depths of space, a spiral galaxy twists like a cosmic Kraken, its bright core and distinct arms encircled by a sea of stars against the dark expanse.
Did the Milky Way form by slowly accreting matter or by devouring its neighboring galaxies? At last, we're uncovering our own history.
Known as orphaned planets, rogue planets, or planets without parent stars, these "outliers" might be the most common type of planet overall.
Our galactic home in the cosmos — the Milky Way — is only one of trillions of galaxies within our Universe. Is one of them truly our "twin?"