How can water exist so close to a supermassive black hole?

Water survives inside the dense, expanding gas envelope blown off by the star IRS 3. The thick layers of gas shield delicate water molecules from the intense high-energy radiation generated near Sagittarius A*.

What kind of star is IRS 3?

IRS 3 is an asymptotic giant branch star, meaning it is an evolved star near the end of its life. It has a mass about six times greater than our Sun and is roughly 72 million years old.

How far is IRS 3 from the center of the Milky Way?

IRS 3 is located approximately 0.55 light-years away from Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy.

Why is finding silicate dust in the galactic center important?

Silicate dust provides the raw building material for rocky planets and asteroids. Finding it near a supermassive black hole proves that stars can actively enrich even the most extreme galactic environments with planet-forming ingredients.

Dust and Water Near a Black Hole Found by Webb Telescope

Astronomers used the James Webb Space Telescope to detect dust and water near a black hole at the center of the Milky Way galaxy in the shell of star IRS 3

Astronomers have found unexpected ingredients drifting in the harshest neighborhood of our galaxy. Using powerful infrared sensors, researchers spotted clouds of dust and water near a black hole at the Milky Way's core. These fragile materials surround a dying giant star that continues to eject heavy elements into deep space.

Quick answer: The James Webb Space Telescope detected silicate dust and water vapor around the aging star IRS 3, located just 0.55 light-years from the supermassive black hole Sagittarius A*. This discovery proves that complex molecules and planet-forming building blocks can survive intense galactic radiation.

A Surprising Finding in the Galactic Heart

The center of our galaxy is a violent place. At its very core sits Sagittarius A*, a supermassive black hole with the mass of four million Suns. Powerful gravitational forces pull on nearby stars. High-energy radiation floods the surrounding space. For a long time, scientists believed fragile materials like water and fine dust could not easily form or last in such an extreme environment.

New observations from the James Webb Space Telescope have overturned that view. An international team of researchers aimed Webb's infrared mirrors directly at the galactic core. They discovered that an aging star called IRS 3 is actively making new cosmic dust. Even more surprisingly, they found water molecules floating inside the thick cloud around the star.

This finding shows that the core of our galaxy is far more creative than once thought. Even right next to a giant gravitational monster, stars continue to seed space with the basic ingredients needed for future generations of worlds.

Meet IRS 3: The Dying Giant Star

IRS 3 is an extraordinary stellar neighbor to our central black hole. The star sits merely 0.55 light-years away from Sagittarius A*. For comparison, that is only about an eighth of the distance between our Sun and its nearest stellar neighbor, Proxima Centauri.

Astronomers classify IRS 3 as an asymptotic giant branch star. This name refers to an advanced stage near the very end of a star's normal life cycle. Stars enter this phase after burning through the hydrogen and helium fuel inside their cores.

Key characteristics of IRS 3 include:

Stellar Mass: Approximately six times heavier than our Sun.
Estimated Age: Roughly 72 million years old.
Distance to Black Hole: Only 0.55 light-years from Sagittarius A*.
Current Phase: Asymptotic giant branch, marked by strong stellar winds and high mass loss.
Brightness: One of the brightest mid-infrared objects visible in the galactic center.

Because IRS 3 is so massive, it burns through its fuel relatively quickly. As it swells and cools, powerful stellar winds blow outward from its surface. These winds push vast quantities of gas and newly forged elements into the surrounding void.

How Webb Detected Dust and Water Near a Black Hole

Studying objects near the center of the Milky Way is notoriously difficult. Thick lanes of dark dust block regular optical light from traveling across the 26,000 light-years between Earth and the galactic core. Fortunately, mid-infrared light passes straight through these dense curtains.

Astronomers utilized Webb's Mid-Infrared Instrument, known as MIRI. MIRI splits incoming infrared light into detailed color bands, much like a prism breaks sunlight into a rainbow. This technique is called spectroscopy. Every chemical element and molecule absorbs and emits light at specific wavelengths, leaving behind a unique chemical fingerprint.

Previous ground-based studies hinted that IRS 3 might be rich in carbon. Webb's continuous mid-infrared spectrum told a completely different story. The telescope detected clear spectral spikes caused by silicate dust, a mineral made from silicon and oxygen. Along with these silicate grains, the data revealed unmistakable chemical signatures of water vapor drifting throughout the stellar wind.

Inside the Massive Shell of IRS 3

By matching Webb's observations with computer simulations of light moving through gas clouds, researchers mapped out the physical shape of the envelope around IRS 3. They found a giant, layered shell expanding far into space.

This cocoon of gas and dust displays extreme internal changes:

Enormous Size: The dust shell reaches outward roughly 10,000 astronomical units from the star. One astronomical unit equals the distance between Earth and the Sun, making this envelope roughly 10,000 times wider than Earth's orbital path.
Extreme Temperature Drop: Near the surface of the star, temperatures reach about 1,200 Kelvin (around 1,700 degrees Fahrenheit). At the outer edges of the shell, the temperature plunges to a freezing 100 Kelvin (about minus 280 degrees Fahrenheit).
Layered Shells: The ejected matter forms distinct concentric layers, recording separate pulses of mass loss from the dying star.

As hot gas flows away from the star, it cools rapidly. Once the gas cools enough, atoms link together to form solid mineral grains and water molecules before galactic radiation can destroy them.

Why Molecule Survival Near Sagittarius A* Matters

Scientists previously wondered whether cosmic dust and water could survive so close to a supermassive black hole. Black holes pull in surrounding gas. As that matter spirals inward, it heats up and shoots intense ultraviolet and X-ray radiation across nearby space. This harsh energy normally breaks apart delicate chemical bonds.

The survival of water around IRS 3 proves that dense stellar winds provide a protective shield. The thick outer layers of gas block incoming destructive rays, allowing fragile compounds to thrive in the shaded pockets inside the envelope.

This discovery changes our understanding of cosmic recycling. When large stars die, they enrich interstellar space with elements like oxygen, silicon, and iron. If these materials survive near galactic centers, they can eventually collapse into new nebulae, forming younger stars, rocky planets, and possibly water-bearing asteroids.

The MICONIC Programme and Future Discoveries

These groundbreaking observations were gathered as part of the Mid-Infrared Characterisation of Nearby Iconic galaxy Centres programme, or MICONIC. This dedicated research project uses Webb to inspect the crowded cores of galaxies with unprecedented sharpness.

Astronomers plan to study other luminous stars drifting near Sagittarius A*. By analyzing more stellar envelopes, researchers hope to determine exactly how much dust dying stars contribute to the galactic core each year. Every new dataset helps scientists piece together how galaxies evolve, recycle their matter, and generate the chemical foundations for new solar systems.

What to explore next

Learn how cosmic giants warp spacetime in our guide to /black-holes.
Discover how dying stars enrich space across the cosmos in /stars-and-galaxies.
See how space telescopes capture deep-sky objects in /missions.