Messier 83

A big group of stars is far away.

It looks like a spinning toy. We call it the Southern Pinwheel. It is very bright in the sky. You can see it with tools.

It has long arms that swirl. These arms make many new stars. A small group of stars once bumped into it. This made even more stars grow. We might even find a black hole in the middle. It is a very busy place in space.

Messier 83 is a big group of stars. People call it the Southern Pinwheel Galaxy. It is about 15 million light-years away.

You can see it with binoculars. It is one of the brightest galaxies in the sky. It is a barred spiral galaxy. This means it has a bar-shaped part in its center. It also has long, swirling arms.

These arms are loosely wound. They help make new stars. Scientists found many new stars in the outer parts of the galaxy. They once thought those parts lacked the right materials.

A small galaxy named NGC 5253 is nearby. These two likely bumped into each other. This made many stars grow in their centers.

We have seen six supernovae in M83. A supernova is a huge star explosion. One was named SN 1983N. It was a special kind of explosion. It let out a lot of iron. This was the first time we saw that much iron from an explosion. We may also find a supermassive black hole in the center.

Messier 83 is a huge and beautiful galaxy. Many people call it the Southern Pinwheel Galaxy.

It is located about 15 million light-years away from us. You can find it near the borders of Hydra and Centaurus. It is a barred spiral galaxy. This means it has a bar-shaped center. The arms of the galaxy swirl around that bar. It is very bright in the night sky. You can even see it using binoculars.

This galaxy has a very special shape. Its arms are loosely wound around the center. This is called a weak-barred spiral structure. Scientists use a system called De Vaucouleurs to name it. M83 is also known as NGC 5236. A small galaxy named NGC 5253 sits near it. These two likely bumped into each other long ago. This interaction caused starburst activity in their centers. This means many new stars were born there.

People have studied this galaxy for a long time. Nicolas-Louis de Lacaille discovered it in 1752. He found it at the Cape of Good Hope. Later, Charles Messier added it to his famous catalogue. He did this in March 1781.

Astronomers keep finding new things about it today. In 2008, NASA found many new stars in the outer edges. People used to think those areas lacked the right materials. Now, we might find a supermassive black hole there too.

We have seen six huge star explosions in M83. These are called supernovae. One happened on May 5, 1923, and was found by Carl Otto Lampland. Another was found by William Liller in 1945. Guillermo Haro found one in 1950. Howard S. Gates found a fourth in 1957. John C. Bennett found a fifth in 1968. Finally, Robert Evans found one in 1983.

This last one, SN 1983N, was very special. It was the first Type I supernova with radio waves detected.

This galaxy is part of a larger neighborhood. It sits in the Centaurus A/M83 Group. This group has two main parts. Centaurus A is the center of one part. M83 is at the center of the other part. These two parts are physically very close to each other. They do not move away from one another.

M83 is like a giant spinning wheel of stars. It helps us understand how big galaxies work. It shows us how stars are born and die.

Messier 83 is a massive barred spiral galaxy. It is also known as the Southern Pinwheel Galaxy or NGC 5236. This galaxy is one of the closest and brightest barred spiral galaxies in our sky. It is located approximately 15 million light-years away. You can find it near the borders of the Hydra and Centaurus constellations. Because it is so bright, you can even see it using binoculars.

The structure of M83 is quite specific. Astronomers use the De Vaucouleurs system to classify its shape. M83 is classified as SAB(s)c. The 'SAB' label means it is a weak-barred spiral. This means it has a bar-shaped center, but the bar is not very strong. The '(s)' part indicates it is a pure spiral structure without a ring. Finally, the 'c' means the spiral arms are loosely wound. This shape gives it the nickname of the Southern Pinwheel.

Many interesting processes happen within the arms of this galaxy. According to density wave theory, star formation happens more quickly along the leading edge of the spiral arms. This means new stars are born in specific patterns as the arms move. In 2008, NASA's Galaxy Evolution Explorer project found something surprising. It reported large numbers of new stars in the outer reaches of the galaxy. These stars were far from the center. Scientists previously thought these outer areas lacked the materials needed to make stars.

Gravity also plays a huge role in the history of M83. A peculiar dwarf galaxy called NGC 5253 lies near M83. It is likely that these two galaxies interacted within the last billion years. This interaction caused starburst activity in their central regions. Starburst activity is a period of intense star formation. Additionally, researchers found first clues in April 2025 regarding a possible supermassive black hole. This black hole might exist at the very center of M83.

Humans have been observing M83 for centuries. Nicolas-Louis de Lacaille discovered the galaxy on 17 February 1752. He made this discovery at the Cape of Good Hope. Later, Charles Messier added it to his famous Messier Catalogue in March 1781. Since then, astronomers have recorded many important events. They have observed six different supernovae, which are massive explosions of dying stars. These explosions help us learn about the life cycles of stars within the galaxy.

One supernova, named SN 1983N, was particularly significant. It was discovered by Robert Evans from Australia on 3 July 1983. On 6 July, scientists observed it with the Very Large Array. This was the first time radio emissions were detected from a Type I supernova. The explosion reached its peak optical brightness on 17 July. About one year after the explosion, scientists discovered a large amount of iron in the ejecta. This was the first time such a large amount of iron was clearly detected from a supernova.

M83 is part of a larger cosmic neighborhood. It sits at the center of one of two subgroups in the Centaurus A/M83 Group. Centaurus A is at the center of the other subgroup. These two subgroups are physically close to each other. They do not appear to be moving relative to one another. By studying M83, scientists can better understand how galaxy groups and star formation work across the universe.