Stunning 'Einstein ring' warping space-time captured by Euclid

The universe is full of mysteries, many of which remain unseen until technology advances enough to reveal them. Scientists have long sought deeper insights into dark matter, dark energy, and the fundamental forces shaping the cosmos.

The European Space Agency’s Euclid telescope was designed to explore these mysteries, offering a new perspective on the structure of the universe, including rare phenomena like the Einstein ring.

Euclid launched on July 1, 2023, beginning a six-year mission to map billions of galaxies and reveal the invisible forces shaping their movements. Before the spacecraft could start its full survey, scientists needed to test its instruments and verify that everything functioned correctly.

During this testing phase in September 2023, Euclid sent back a series of preliminary images. These images were meant to confirm the telescope’s alignment and functionality.

A surprise in blurry images

Bruno Altieri, a Euclid Archive Scientist, was among those analyzing the incoming data. Even in the out-of-focus images, he noticed something unusual. A subtle but striking pattern caught his attention, prompting him to investigate further.

“I look at the data from Euclid as it comes in,” noted Altieri. “Even from that first observation, I could see it, but after Euclid made more observations of the area, we could see a perfect Einstein ring. For me, with a lifelong interest in gravitational lensing, that was amazing.”

This unexpected discovery was hiding in a familiar galaxy, NGC 6505, located about 590 million light-years from Earth. In cosmic terms, this is remarkably close.

Despite its proximity and the fact that astronomers have studied this galaxy for over a century, the phenomenon within it had remained unnoticed.

Science behind the Einstein ring

At the heart of this discovery is the phenomenon of gravitational lensing.

Albert Einstein’s general theory of relativity predicts that massive objects bend light as it travels through space. This effect, known as gravitational lensing, allows galaxies and clusters of galaxies to act as giant cosmic magnifiers.

The Einstein ring around NGC 6505 is created by light from a much more distant galaxy located 4.42 billion light-years away. As the light from this background galaxy passes near NGC 6505, the gravity of the foreground galaxy bends and distorts it.

When the alignment is perfect, the light forms a striking circle around the foreground object, creating what astronomers call an Einstein ring.

A rare and valuable discovery

Strong gravitational lenses like this are rare. They provide crucial opportunities for astronomers to study the properties of dark matter and measure the expansion of the universe.

“An Einstein ring is an example of strong gravitational lensing,” explained Conor O’Riordan from the Max Planck Institute for Astrophysics.

“All strong lenses are special, because they’re so rare, and they’re incredibly useful scientifically. This one is particularly special, because it’s so close to Earth and the alignment makes it very beautiful.”

This Einstein ring is unique not only because of its proximity but also because of its perfect shape. The alignment between the foreground and background galaxies is nearly exact, making the ring exceptionally clear.

Such clarity allows scientists to study the properties of both galaxies in greater detail than ever before.

Einstein ring features revealed by Euclid

One of the most astonishing aspects of this discovery is that it was made within a well-known galaxy. NGC 6505 was first documented in 1884, yet this remarkable feature within it had remained unnoticed until Euclid’s high-resolution instruments captured it.

“I find it very intriguing that this ring was observed within a well-known galaxy, which was first discovered in 1884,” said Valeria Pettorino, ESA Euclid Project Scientist.

“The galaxy has been known to astronomers for a very long time. And yet this ring was never observed before. This demonstrates how powerful Euclid is, finding new things even in places we thought we knew well.”

“This discovery is very encouraging for the future of the Euclid mission and demonstrates its fantastic capabilities.”

If such a spectacular structure was waiting to be found in a well-documented galaxy, scientists wonder what other surprises Euclid might uncover as it explores deeper into the universe.

Mapping the universe in 3D

The Euclid telescope is designed to go far beyond individual discoveries like this Einstein ring.

Its primary mission is to create the most extensive 3D map of the universe ever constructed. Over the next six years, Euclid will survey more than a third of the sky, analyzing billions of galaxies and tracing their distribution across cosmic time.

One of the most exciting aspects of Euclid’s mission is its ability to find strong gravitational lenses. Scientists estimate that the telescope will discover around 100,000 of these lenses, providing an enormous dataset for studying dark matter and dark energy.

Until now, fewer than 1,000 strong lenses had been identified, and even fewer had been imaged with high resolution. The discovery of this Einstein ring so early in the mission signals that Euclid is on track to surpass all expectations.

“Euclid is going to revolutionize the field, with all this data we’ve never had before,” said O’Riordan.

Analyzing billions of galaxies

While the Einstein ring around NGC 6505 is an exciting find, Euclid’s primary goal is even more ambitious. The telescope is designed to study weak gravitational lensing, a subtle effect that slightly stretches and shifts the shapes of background galaxies.

Unlike strong lensing, which creates dramatic rings, weak lensing is far more difficult to detect. To measure this effect, scientists will analyze the shapes of billions of galaxies and use this data to map the distribution of dark matter across the cosmos.

Euclid began its full survey on February 14, 2024, and is steadily building a comprehensive view of the Universe’s structure. With each new observation, it has the potential to reveal hidden patterns and unlock secrets that have remained concealed for billions of years.

A mission filled with possibilities

The discovery of this Einstein ring is just the beginning. Euclid’s ability to capture such fine details in a nearby galaxy hints at the extraordinary discoveries that await in the coming years.

Scientists anticipate that as more data arrives, Euclid will provide unprecedented insights into the nature of dark matter, dark energy, and the forces that shape the universe.

By pushing the boundaries of what we can observe, Euclid is not only deepening our understanding of the cosmos but also proving that even in well-explored regions, there is always something new waiting to be discovered.

Image Credit: European Space Agency

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–