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Phoenix Cluster

Adapted from Wikipedia · Discoverer experience

A colorful space image of the Phoenix Cluster, showing X-ray and optical data from telescopes, revealing cavities and filaments in the distant universe.

The Phoenix Cluster (SPT-CL J2344-4243) is a huge grouping of galaxies called a galaxy cluster. It is found in the southern sky near a pattern of stars called the constellation of Phoenix. Astronomers first found this cluster in 2010 using a special telescope called the South Pole Telescope.

This cluster is one of the biggest we know, with a mass about 2 million billion times more than our Sun. It shines very brightly in a kind of light called X-rays, more than any other big cluster found so far. The Phoenix Cluster is very far away, about 8.61 billion light-years from Earth.

Astronomers have counted about 42 galaxies in the Phoenix Cluster so far, but there might be as many as 1,000 hidden inside it. Studying clusters like this helps scientists learn about how galaxies and the universe itself grow and change over time.

Discovery

The Phoenix Cluster was first found during a big sky survey done by the South Pole Telescope in Antarctica. This cluster was one of 26 galaxy clusters spotted in the survey, and it was a brand new discovery. It stands out because it gives off more X-rays than any other known cluster. Near the center of the cluster, scientists also found a very bright galaxy called Phoenix A.

Characteristics

Artist's depiction of the center of the Phoenix Cluster, showing the central black hole and its accretion disc that fuels two powerful jets emanating from the nucleus

The Phoenix Cluster is very special because of its extreme properties. Scientists have studied it a lot and found that it has a very strong cooling flow. This means that material in the cluster is cooling down very quickly, much faster than in other clusters.

One amazing thing about the Phoenix Cluster is that it shines very brightly in X-rays—brighter than any other known cluster. The central galaxy, Phoenix A, is forming new stars at a very fast rate, much faster than our own Milky Way.

Components

The central galaxy of the Phoenix Cluster, called Phoenix A, is a very large and special galaxy. It has an active center powered by a supermassive black hole. This galaxy is making new stars at an amazing rate, faster than many other galaxies.

The black hole at the center of Phoenix A might be one of the biggest we know. It could have a mass of about 100 billion times that of our Sun. If it were placed where our Sun is, its edge would reach far beyond the planet Pluto. This huge black hole helps shape the galaxy and the cluster around it.

JWST observations

In 2025, NASA's James Webb Space Telescope found an important clue about the Phoenix Cluster. It discovered a special kind of gas that is just the right temperature to help new stars form quickly in the cluster. This gas is much hotter than the cool gas but not as hot as the very warm gas around it, and this has never been seen in other clusters of galaxies before.

Images

A stunning view of the Seyfert 2 galaxy known as Phoenix A, captured by the DESI Legacy Surveys.
An artist's view of the giant ring system of exoplanet J1407b as seen from one of its potential moons.
An artist’s drawing of a beautiful sunset on a distant planet, with bright stars shining in the sky.
A self-portrait of NASA's Mars rover Curiosity taken on the red planet, showing the rover at a rock-drilling site.
A stunning view of Earth rising over the Moon, captured by astronauts during the Apollo 8 mission in 1968.

This article is a child-friendly adaptation of the Wikipedia article on Phoenix Cluster, available under CC BY-SA 4.0.

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