Messier 87

M87 is a giant group of stars.

It is very big. It has trillions of stars. It is shaped like a ball. This is different from our home.

A dark spot sits in the middle.

This spot is very strong. It shoots out a long beam. This beam moves very fast.

Scientists use tools to see it. They even took a picture of the dark spot. It is a wonder to see.

M87 is a giant elliptical galaxy.

An elliptical galaxy is shaped like a ball. It does not look like a flat disk. M87 is one of the biggest galaxies nearby. It holds several trillion stars.

Most stars in M87 are old. The stars move in random ways. This movement helps keep the galaxy in its round shape. M87 also has many globular clusters. These are large groups of stars. M87 has about 15,000 of them. Our Milky Way only has about 200.

At the center of M87 is a supermassive black hole. This is a very heavy object that pulls things in.

This black hole makes a long jet. The jet is made of plasma, which is a hot gas. This jet shoots out from the center. It travels at a very high speed.

Scientists used the Event Horizon Telescope to see the black hole. They released a famous image of it in 2019. This helped us learn more about how galaxies work.

Messier 87 is a huge elliptical galaxy in the Virgo constellation.

It is one of the largest and most massive galaxies in our local universe. Unlike our Milky Way, which is shaped like a flat disk, M87 is shaped like a ball or an egg. This shape is called an elliptical galaxy. It has no clear dust lanes to mark its structure. Instead, the light gets dimmer as you move away from the center. The galaxy contains several trillion stars.

These stars move in random directions to keep the galaxy's shape. This is different from spiral galaxies where stars move in more orderly paths.

Inside M87, there are many special groups of stars called globular clusters. These are large, tight bunches of stars that orbit the galaxy. M87 has about 15,000 of these clusters. To compare, our own Milky Way only has about 150 to 200. At the very center of the galaxy sits a supermassive black hole. This black hole is a primary part of the active galactic nucleus. It is so heavy that it pulls things toward it with great force. This central area also creates a long jet of energetic plasma.

This jet shoots out from the core and travels at a relativistic speed, which means it moves very close to the speed of light.

People have been studying this galaxy for a long time. A French astronomer named Charles Messier found it in 1781. He originally thought it was a nebula, which is a cloud of gas or dust. Later, in the 1880s, John Dreyer included it in a new catalog called the New General Catalogue. In 1918, an American astronomer named Heber Curtis noticed the galaxy had no spiral shape. He also saw a strange, straight ray connected to the center. In 1922, Edwin Hubble helped scientists understand that M87 was a galaxy far outside our own.

Scientists have used many tools to learn about M87's secrets. In 1978, researchers found evidence that the central mass was five billion times the mass of our Sun. In 2017, the Event Horizon Telescope (EHT) collected data to look at the black hole directly. They released a famous processed image of the black hole's shadow on April 10, 2019.

In March 2021, the EHT team showed a new image using polarized light. This helps scientists study the forces that create quasars. The galaxy is about 55 million light-years away from Earth. It is the second-brightest galaxy in the northern Virgo Cluster.

Understanding M87 helps us see how big galaxies grow. Scientists believe elliptical galaxies like this form when smaller galaxies crash into each other. By looking at the stars, researchers found that M87 likely swallowed a medium-sized spiral galaxy about a billion years ago.

This process adds new stars and gas to the giant galaxy. We can also see how the galaxy interacts with its neighbors. There are even streams of stars that might have been pulled away by the gravity of M87. Studying this galaxy is like looking at a giant history book of the universe.

Messier 87, often called M87, is a massive supergiant elliptical galaxy.

It is located in the constellation Virgo. This galaxy is one of the largest and most massive systems in our local universe. Unlike the flat, disk-shaped Milky Way, M87 has an ellipsoidal shape. This means it looks more like a rounded ball or an egg. It is categorized as an E0 galaxy because it shows no obvious flattening.

It is also called a cD galaxy because it has a large, diffuse envelope of stars around its nucleus. M87 is a vital subject for astronomers studying how galaxies evolve and grow.

The structure of M87 is defined by its massive scale and unique movement. It contains several trillion stars that are spread out in a nearly spherical way. These stars do not follow the orderly, circular paths seen in spiral galaxies. Instead, they move in random orbital motions. This random movement is what maintains the galaxy's elliptical shape. The density of these stars is highest at the center. The luminosity, or brightness, decreases as you move further away from the core. M87 also contains about 15,000 globular clusters. These are tight groups of stars that orbit the galaxy. This is a much larger population than the 150 to 200 clusters found in the Milky Way.

At the very center of M87 lies an active galactic nucleus. This nucleus is powered by a supermassive black hole. This black hole acts as a massive engine for the galaxy. It creates a powerful jet of energetic plasma. This jet originates at the core and extends at least 5,000 light-years into space. The jet travels at a relativistic speed. This means it moves at a speed close to the speed of light.

The galaxy is also a strong source of multi-wavelength radiation. It is particularly bright in radio waves. This makes it a very important target for radio telescopes across the world.

History shows how our understanding of M87 has changed over time. The French astronomer Charles Messier discovered the object in 1781. At that time, he cataloged it as a nebula. In the 1880s, John Dreyer included it in the New General Catalogue as NGC 4486. In 1918, Heber Curtis noticed the galaxy lacked a spiral structure. He also observed a straight ray connected to the nucleus. In 1922, Edwin Hubble helped redefine what M87 was. He first classified it as a globular nebula. By 1926, he distinguished extragalactic nebulae as independent star systems. He then classified M87 as an elliptical extragalactic nebula.

Modern technology has allowed us to measure M87 with incredible precision. We know the galaxy is approximately 55 million light-years from Earth. It is the second-brightest galaxy in the northern Virgo Cluster. Scientists have used many methods to estimate its distance. These include measuring the brightness of planetary nebulae and using red giant stars. The mass of the central black hole has been studied extensively. In 1978, models suggested a mass of five billion solar masses. Later, data from the Hubble Space Telescope suggested a mass of 2.4 billion solar masses.

In 2017, the Event Horizon Telescope (EHT) captured data to image the black hole's shadow. A processed image was released on 10 April 2019.

There are several surprising facts about the mass and composition of M87. The galaxy's diameter is about 132,000 light-years. This is about 51% larger than the diameter of the Milky Way. Within a radius of 2.4 kiloparsecs, the mass is twice that of the Milky Way. However, most of this mass is not made of stars. Only about one-sixth of the mass is in the form of stars. The rest is likely dark matter or diffuse gas. The interstellar medium consists of gas enriched by evolved stars. The galaxy also experiences an infall of gas. This happens at a rate of two to three solar masses per year. Most of this gas may be pulled into the core.

Studying M87 helps scientists understand the broader life cycles of galaxies. Elliptical galaxies are thought to form through mergers. This happens when smaller galaxies collide and join together. Observations of planetary nebulae suggest M87 absorbed a medium-sized spiral galaxy about a billion years ago.

We can also see evidence of this through tidal stripping. This is when the gravity of a large galaxy pulls stars away from a smaller one. There are even linear streams of stars to the northwest of M87. These streams may be remnants of smaller galaxies being pulled in. M87 serves as a massive laboratory for studying gravity and galactic evolution.