The JWST is Re-Writing Astronomy Textbooks

The first JWST Deep Field Image, showing large distant galaxies. The telescope's observations are revealing the previously unseen and are forcing a re-write of astronomy textbooks. Image Credit: NASA, ESA, CSA, STScI

When the James Webb Space Telescope was launched at the end of 2021, we expected stunning images and illuminating scientific results. So far, the powerful space telescope has lived up to our expectations. The JWST has shown us things about the early Universe we never anticipated.

Some of those results are forcing a rewrite of astronomy textbooks.

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Not All Black Holes are Ravenous Gluttons

This artist’s impression shows the record-breaking quasar J059-4351, the bright core of a distant galaxy that is powered by a supermassive black hole. The light comes from gas and dust that's heated up before it's drawn into the black hole. Credit: ESO/M. Kornmesser

Some Supermassive Black Holes (SMBHs) consume vast quantities of gas and dust, triggering brilliant light shows that can outshine an entire galaxy. But others are much more sedate, emitting faint but steady light from their home in the heart of their galaxy.

Observations from the now-retired Spitzer Space Telescope help show why that is.

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The Stellar Demolition Derby in the Centre of the Galaxy

This illustration shows stars orbiting close to the Milky Way's central supermassive black hole. The black hole accelerates stars nearby and sends them crashing into one another. Credit: ESO/L. Calçada/Spaceengine.org

The region near the Milky Way’s centre is dominated by the supermassive black hole that resides there. Sagittarius A*’s overwhelming gravity creates a chaotic region where tightly packed, high-speed stars crash into one another like cars in a demolition derby.

These collisions and glancing blows change the stars forever. Some become strange, stripped-down, low-mass stars, while others gain new life.

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A Black Hole Has Cleared Out Its Neighbourhood

An artist's illustration of a supermassive black hole (SMBH.) The SMBH in a distant galaxy expelled all the material in its accretion disk, clearing out a vast area. Image Credit: ESA

We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.

But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.

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A Black Hole Nibbles on a Star Every 22 Days, Slowly Consuming it

A star is ripped apart by a black hole. Credit: Mark Garlick

Astronomers working with NASA’s Neil Gehrels Swift Observatory have spotted something unusual. The observatory’s X-Ray Telescope (XRT) has captured emissions from a supermassive black hole (SMBH) in a galaxy about 500 million light-years away. The black hole is repeatedly feeding on an unfortunate star that came too close.

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M87 Galaxy Reconstructed in Thrilling 3D

A photo of the huge elliptical galaxy M87 [left] is compared to its three-dimensional shape as gleaned from meticulous observations made with the Hubble and Keck telescopes [right]. Image Credit: NASA, ESA, J. Olmsted (STScI), F. Summers (STScI)C. Ma (UC Berkeley); CC BY 4.0

In astronomy, we speak casually of extremely large numbers and extremely vast distances as if they’re trivial. A supermassive black hole can have several billion solar masses, a distant quasar is 500 million light-years away, etc. Objects like galaxies that are mere tens of millions of light years away start to seem familiar.

But even though our Wikipedia pages are full of data on distant objects, there’s a deceptive lack of understanding of some of their basic properties. Take Messier 87, for example, a galaxy often talked about and seen in images. It’s noteworthy for being home to the first black hole ever imaged.

It’s so far away that astronomers have no real idea what its three-dimensional shape is.

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Astronomers Spot a Rogue Supermassive Black Hole, Hurtling Through Space Leaving Star Formation in its Wake

This artist's conception illustrates a supermassive black hole (central black dot) at the core of a young, star-rich galaxy. Now astronomers have found a rogue SMBH travelling through space. Image credit: NASA/JPL-Caltech

Supermassive black holes (SMBHs) lurk in the center of large galaxies like ours. From their commanding position in the galaxy’s heart, they feed on gas, dust, stars, and anything else that strays too close, growing more massive as time passes. But in rare circumstances, an SMBH can be forced out of its position and hurtle through space as a rogue SMBH.

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Hungry Black Hole was Already Feasting 800 Million Years After the Big Bang

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Black holes swallow everything—including light—which explains why we can’t see them. But we can observe their immediate surroundings and learn about them. And when they’re on a feeding binge, their surroundings become even more luminous and observable.

This increased luminosity allowed astronomers to find a black hole that was feasting on material only 800 million years after the Universe began.

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The Donut That Used To Be a Star

This sequence of artist's illustrations shows how a black hole can devour a bypassing star. 1) A normal star passes near a supermassive black hole in the center of a galaxy. 2) The star's outer gasses are pulled into the black hole's gravitational field. 3) The star is shredded as tidal forces pull it apart. 4) The stellar remnants are pulled into a donut-shaped ring around the black hole, and will eventually fall into the black hole, unleashing a tremendous amount of light and high-energy radiation. Credit: NASA, ESA, Leah Hustak (STScI)

The death of a star is one of the most dramatic natural events in the Universe. Some stars die in dramatic supernova explosions, leaving nebulae behind as shimmering remnants of their former splendour. Some simply wither away as their hydrogen runs out, billowing into a red giant as they do so.

But others are consumed by behemoth black holes, and as they’re destroyed, the black hole’s powerful gravity tears the star apart and draws its gas into a donut-shaped ring around the black hole.

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A Black Hole is Savoring its Meal, Feeding on the Same Star Over and Over Again

This illustration shows a glowing stream of material from a star, being devoured and torn to shreds by a supermassive black hole. Credit: NASA/JPL-Caltech

Something extraordinary happens about every 10,000 to 100,000 years in galaxies like the Milky Way. An unwary star approaches the supermassive black hole (SMBH) at the galaxy’s center and is torn apart by the SMBH’s overpowering gravity. Astronomers call the phenomenon a tidal disruption event (TDE.)

Usually, a TDE spells doom for the star as its gas is torn away into the black hole’s accretion ring, causing a bright flaring visible for hundreds of millions of light years. But researchers have found one black hole that’s playing with its food.

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