Messier 87

Messier 87, also known as Virgo A or NGC 4486, is a supergiant elliptical galaxy in the constellation Virgo. It is one of the largest and most massive galaxies close to us, containing several trillion stars. Unlike spiral galaxies, which have a disk shape with spiral arms, Messier 87 has a smooth, round shape typical of giant elliptical galaxies.

The French astronomer Charles Messier discovered Messier 87 in 1781. It is located about 53 million light-years from Earth and is the second-brightest galaxy in the Virgo Cluster. Messier 87 has a large number of globular clusters—about 15,000—orbiting around it, compared to only 150–200 around our own Milky Way galaxy.

At the center of Messier 87 lies a supermassive black hole. In 2019, the Event Horizon Telescope released the first image of this black hole, showing its shadow against the glowing material around it. This was a major breakthrough in understanding black holes and how they influence the galaxies around them.

Messier 87 is also a strong source of radio waves and other types of radiation. It has a jet of energetic plasma shooting out from its core, stretching for thousands of light-years. This galaxy continues to be a popular target for both amateur and professional astronomers studying the universe.

Observation history

In Hubble's galaxy classification scheme, M87 is an E0 galaxy.

In 1781, the French astronomer Charles Messier published a catalogue of fuzzy objects to help others not mistake them for comets. M87 was the eighty-seventh object in this list. Later, it was also listed as NGC 4486 in another star chart made by John Dreyer.

Over time, astronomers learned more about M87. In 1922, Edwin Hubble helped us understand that M87 was a giant elliptical galaxy, not just a cloudy object in the sky. In 2017, the Event Horizon Telescope captured the first ever picture of a black hole’s shadow, and it was of the black hole at the center of M87.

Visibility

Messier 87, or M87, is located near the edge of the Virgo constellation, close to the constellation Coma Berenices. You can spot this galaxy with a small telescope, about 6 cm (2.4 in) in size. It stretches across an area of 7.2 × 6.8 arcminutes. The galaxy has a very bright center, and seeing its jet usually needs special photography. Before 1991, only one astronomer, Otto Struve, had seen the jet with a telescope, using a very large Hooker telescope. Today, larger amateur telescopes can sometimes observe it under perfect conditions.

Properties

Stellar velocity map of the central region of M87, showing the motion of stars relative to Earth: away towardsThe image shows a slight rotation in the vertical plane (the lower right moving toward earth, the upper left moving away), showing that M87 is rotating slowly.

Messier 87, or M87, is a huge elliptical galaxy in the constellation Virgo. It is one of the largest and most massive galaxies close to us. M87 appears almost perfectly round and is known for the powerful jet of energetic particles that shoots out from its center.

M87 is about 132,000 light-years wide, which is larger than our own Milky Way. It contains about twice as much mass as the Milky Way, most of which is not in the form of stars. M87 has many smaller galaxies orbiting around it and has pulled in material from other galaxies over time, adding to its size and mass.

Enclosed mass
Radius kpc	Mass ×10¹² M_☉
32	2.4
44	3.0
47	5.7
50	6.0

Components

The core of Messier 87 contains a supermassive black hole, one of the largest known. This black hole has a mass billions of times that of the Sun. Around it is a spinning disk of hot gas, moving at incredible speeds. Scientists have taken pictures of this black hole, showing a dark spot where its shadow appears.

Composite image showing how the M87 system looked, across the entire electromagnetic spectrum, during the Event Horizon Telescope's April 2017 campaign to take the first image of a black hole. Requiring 19 different facilities on the Earth and in space, this image reveals the enormous scales spanned by the black hole and its forward-pointing jet. It shows the image of the larger-scale jet taken by ALMA (upper left), on the same scale as the visible image by the Hubble Space Telescope (center) and the X-ray image by Chandra (upper right).

Messier 87 also shoots out a powerful jet of energy from its center. This jet travels at nearly the speed of light and stretches far from the galaxy. The jet's energy comes from the spinning black hole and can create bright spots and patterns as it moves through space. Astronomers study these jets to learn more about black holes and the galaxies they live in.

Messier 87 is filled with many "globular clusters"—groups of stars bound together by gravity. It has about 15,000 of these clusters, far more than our own Milky Way galaxy, which has only about 150–200. These clusters vary in size and composition, with many located far from the galaxy's center.

Selected elemental abundances in the M87 core
Element	Abundance (solar values)
C	0.63 ± 0.16
N	1.64 ± 0.24
O	0.58 ± 0.03
Ne	1.41 ± 0.12
Mg	0.67 ± 0.05
Fe	0.95 ± 0.03

Environment

Photograph of Markarian's Chain of Galaxies, taken through a widefield telescope. M87 is visible in the bottom left corner

Main article: Virgo Cluster

Messier 87 is located at the center of the Virgo Cluster, a group of about 2,000 galaxies. This cluster is part of an even larger structure called the Virgo Supercluster, which includes our own Local Group and the Milky Way. Messier 87 is likely the largest galaxy in this cluster and seems to be very still compared to others. The Virgo Cluster has a thin, hot gas that gives off X-rays, and its total mass is estimated to be between 0.15 and 1.5 times 10¹⁵ times the mass of the Sun ¹.