Messier 87

Messier 87

Messier 87 (M87), also known as NGC 4486, is a giant elliptical galaxy in the constellation Virgo. It is one of the most massive galaxies in the local universe and is notable for its large population of globular clusters and a supermassive black hole at its center.

Discovery and Observation

Messier 87 was discovered by the French astronomer Charles Messier on March 18, 1781. It was included in his catalog of comet-like objects as the 87th entry. M87 is located in the Virgo Cluster, a group of galaxies in the Virgo constellation, and is one of the brightest and largest galaxies in this cluster.

Characteristics

Structure

M87 is classified as an elliptical galaxy, specifically a type E0, indicating it has a nearly spherical shape. Unlike spiral galaxies, elliptical galaxies like M87 lack a distinct disk and spiral arms. M87 has a smooth, featureless light profile that decreases in brightness with distance from the center.

Size and Mass

M87 is one of the largest galaxies in the local universe, with a diameter of approximately 120,000 light-years. It contains an estimated 200 trillion stars and has a total mass of about 2.4 trillion solar masses. The galaxy's mass is dominated by dark matter, which makes up about 90% of its total mass.

Globular Clusters

M87 is known for its large population of globular clusters, with estimates ranging from 12,000 to 15,000. These clusters are tightly bound groups of stars that orbit the galaxy's core. The high number of globular clusters is indicative of M87's massive size and gravitational influence.

Supermassive Black Hole

At the center of M87 lies a supermassive black hole, one of the most massive known, with a mass of about 6.5 billion solar masses. This black hole was famously imaged by the Event Horizon Telescope in 2019, providing the first direct visual evidence of a black hole's event horizon.

Jet

M87 is also known for its prominent relativistic jet, which extends about 5,000 light-years from the galaxy's core. This jet is composed of high-energy particles ejected at nearly the speed of light, likely powered by the accretion of material onto the supermassive black hole.

Significance in Astronomy

M87 has been extensively studied due to its proximity and the presence of its supermassive black hole. It serves as a key object for understanding the dynamics of elliptical galaxies, the behavior of supermassive black holes, and the mechanisms of jet formation.

Also see

• Virgo Cluster
• Elliptical galaxy
• Supermassive black hole
• Event Horizon Telescope
• Globular cluster

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Messier 73, Jewel Box, (Kappa Crucis Cluster),

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