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Messier 87
Messier 87, with the blue plasma jet of its galactic core clearly visible (composite image of observations by the Hubble Space Telescope in visible and infrared light)
Observation data (J2000 epoch)
Constellation	Virgo
Right ascension	12 30 49.42338
Declination	+12° 23′ 28.0439″
Redshift	0.00428 ± 0.00002
Heliocentric radial velocity	1,284 ± 5 km/s
Distance	16.4 ± 0.5 Mpc (53.5 ± 1.6 Mly)
Apparent magnitude (V)	8.6
Characteristics
Type	E+0-1 pec, NLRG Sy
Size	40.55 kpc (132,000 ly) (25.0 mag/arcsec B-band isophote)
Apparent size (V)	7.2 × 6.8 arcmin
Other designations
Virgo A, Virgo X-1, NGC 4486, UGC 7654, PGC 41361, VCC 1316, Arp 152, 3C 274, 3U 1228+12.

Messier 87 (also known as Virgo A or NGC 4486, generally abbreviated to M87) is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars. One of the largest and most massive galaxies in the local universe, it has a large population of globular clusters—about 15,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs (4,900 light-years), traveling at a relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.

The French astronomer Charles Messier discovered M87 in 1781, and cataloged it as a nebula. M87 is about 16.4 million parsecs (53 million light-years) from Earth and is the second-brightest galaxy within the northern Virgo Cluster, having many satellite galaxies. Unlike a disk-shaped spiral galaxy, M87 has no distinctive dust lanes. Instead, it has an almost featureless, ellipsoidal shape typical of most giant elliptical galaxies, diminishing in luminosity with distance from the center. Forming around one-sixth of its mass, M87's stars have a nearly spherically symmetric distribution. Their population density decreases with increasing distance from the core. It has an active supermassive black hole at its core, which forms the primary component of an active galactic nucleus. The black hole was imaged using data collected in 2017 by the Event Horizon Telescope (EHT), with a final, processed image released on 10 April 2019. In March 2021, the EHT Collaboration presented, for the first time, a polarized-based image of the black hole which may help better reveal the forces giving rise to quasars.

The galaxy is a strong source of multi-wavelength radiation, particularly radio waves. It has an isophotal diameter of 40.55 kiloparsecs (132,000 light-years), with a diffuse galactic envelope that extends to a radius of about 150 kiloparsecs (490,000 light-years), where it is truncated—possibly by an encounter with another galaxy. Its interstellar medium consists of diffuse gas enriched by elements emitted from evolved stars.

Observation history

In 1781, the French astronomer Charles Messier published a catalogue of 103 objects that had a nebulous appearance as part of a list intended to identify objects that might otherwise be confused with comets. In subsequent use, each catalogue entry was prefixed with an "M". Thus, M87 was the eighty-seventh object listed in Messier's catalogue. During the 1880s, the object was included as NGC 4486 in the New General Catalogue of nebulae and star clusters assembled by the Danish-Irish astronomer John Dreyer, which he based primarily on the observations of the English astronomer John Herschel.

In 1918, the American astronomer Heber Curtis of Lick Observatory noted M87's lack of a spiral structure and observed a "curious straight ray ... apparently connected with the nucleus by a thin line of matter." The ray appeared brightest near the galactic center. The following year, supernova SN 1919A within M87 reached a peak photographic magnitude of 11.5, although this event was not reported until photographic plates were examined by the Russian astronomer Innokentii A. Balanowski in 1922.

Identification as a galaxy

In 1922, the American astronomer Edwin Hubble categorized M87 as one of the brighter globular nebulae, as it lacked any spiral structure, but like spiral nebulae, appeared to belong to the family of non-galactic nebulae. In 1926 he produced a new categorization, distinguishing extragalactic from galactic nebulae, the former being independent star systems. M87 was classified as a type of elliptical extragalactic nebula with no apparent elongation (class E0).

In 1931, Hubble described M87 as a member of the Virgo Cluster, and gave a provisional estimate of 1.8 million parsecs (5.9 million light-years) from Earth. It was then the only known elliptical nebula for which individual stars could be resolved, although it was pointed out that globular clusters would be indistinguishable from individual stars at such distances. In his 1936 The Realm of the Nebulae, Hubble examines the terminology of the day; some astronomers labeled extragalactic nebulae as external galaxies on the basis that they were stellar systems at far distances from our own galaxy, while others preferred the conventional term extragalactic nebulae, as galaxy was at that time a synonym for the Milky Way. M87 continued to be labelled as an extragalactic nebula at least until 1954.

Modern research

In 1947, a prominent radio source, Virgo A, was identified with errors in its measured position that overlapped the location of M87. The source was confirmed to be M87 by 1953, and the linear relativistic jet emerging from the core of the galaxy was suggested as the cause. This jet extended from the core at a position angle of 260° to an angular distance of 20″ with an angular width of 2″. In 1969–1970, a strong component of the radio emission was found to closely align with the optical source of the jet. In 1966, the United States Naval Research Laboratory's Aerobee 150 rocket identified Virgo X-1, the first X-ray source in Virgo. The Aerobee rocket launched from White Sands Missile Range on 7 July 1967 yielded further evidence that the source of Virgo X-1 was the radio galaxy M87. Subsequent X-ray observations by the HEAO 1 and Einstein Observatory showed a complex source that included the active galactic nucleus of M87. However, there is little central concentration of the X-ray emission.

M87 has been an important testing ground for techniques that measure the masses of central supermassive black holes in galaxies. In 1978, stellar-dynamical modeling of the mass distribution in M87 gave evidence for a central mass of five billion M_☉ solar masses. After the installation of the COSTAR corrective-optics module in the Hubble Space Telescope in 1993, the Hubble Faint Object Spectrograph (FOS) was used to measure the rotation velocity of the ionized gas disk at the center of M87, as an "early release observation" designed to test the scientific performance of the post-repair Hubble instruments. The FOS data indicated a central black hole mass of 2.4 billion M_☉, with 30% uncertainty. Globular clusters within M87 have been used to calibrate metallicity relations as well.

M87 was observed by the Event Horizon Telescope (EHT) during much of 2017. The event horizon of the black hole at the center was directly imaged by the EHT, then revealed in a press conference on the issue date stated, filtering out from this the first image of a black hole's shadow.

Visibility

M87 is near a high declination limit of the Virgo constellation, abutting Coma Berenices. It lies along the line between the stars Epsilon Virginis and Denebola (Beta Leonis). The galaxy can be observed using a small telescope with a 6 cm (2.4 in) aperture, extending across an angular area of 7.2 × 6.8 arcminutes at a surface brightness of 12.9, with a very bright, 45 arcsecond core. Viewing the jet is a challenge without the aid of photography. Before 1991, the Ukrainian-American astronomer Otto Struve was the only person known to have seen the jet visually, using the 254 cm (100 in) Hooker telescope. In more recent years it has been observed in larger amateur telescopes under excellent conditions.

Properties

In the modified Hubble sequence galaxy morphological classification scheme of the French astronomer Gérard de Vaucouleurs, M87 is categorized as an E0p galaxy. "E0" designates an elliptical galaxy that displays no flattening—that is, it appears spherical. A "p" suffix indicates a peculiar galaxy that does not fit cleanly into the classification scheme; in this case, the peculiarity is the presence of the jet emerging from the core. In the Yerkes (Morgan) scheme, M87 is classified as a type-cD galaxy. A D galaxy has an elliptical-like nucleus surrounded by an extensive, dustless, diffuse envelope. A D type supergiant is called a cD galaxy.

The distance to M87 has been estimated using several independent techniques. These include measurement of the luminosity of planetary nebulae, comparison with nearby galaxies whose distance is estimated using standard candles such as cepheid variables, the linear size distribution of globular clusters, and the tip of the red-giant branch method using individually resolved red giant stars. These measurements are consistent with each other, and their weighted average yields a distance estimate of 16.4 ± 0.5 megaparsecs (53.5 ± 1.63 million light-years).

M87 is one of the most massive galaxies in the local Universe. Its diameter is estimated at 132,000 light-years, which is approximately 51% larger than that of the Milky Way. As an elliptical galaxy, the galaxy is a spheroid rather than a flattened disc, accounting for the substantially larger mass of M87. Within a radius of 32 kiloparsecs (100,000 light-years), the mass is (2.4±0.6)×10 times the mass of the Sun, which is double the mass of the Milky Way galaxy. As with other galaxies, only a fraction of this mass is in the form of stars: M87 has an estimated mass to luminosity ratio of 6.3 ± 0.8; that is, only about one part in six of the galaxy's mass is in the form of stars that radiate energy. This ratio varies from 5 to 30, approximately in proportion to r in the region of 9–40 kiloparsecs (29,000–130,000 light-years) from the core. The total mass of M87 may be 200 times that of the Milky Way.

The galaxy experiences an infall of gas at the rate of two to three solar masses per year, most of which may be accreted onto the core region. The extended stellar envelope of this galaxy reaches a radius of about 150 kiloparsecs (490,000 light-years), compared with about 100 kiloparsecs (330,000 light-years) for the Milky Way. Beyond that distance the outer edge of the galaxy has been truncated by some means; possibly by an earlier encounter with another galaxy. There is evidence of linear streams of stars to the northwest of the galaxy, which may have been created by tidal stripping of orbiting galaxies or by small satellite galaxies falling in toward M87. Moreover, a filament of hot, ionized gas in the northeastern outer part of the galaxy may be the remnant of a small, gas-rich galaxy that was disrupted by M87 and could be feeding its active nucleus. M87 is estimated to have at least 50 satellite galaxies, including NGC 4486B and NGC 4478.

The spectrum of the nuclear region of M87 shows the emission lines of various ions, including hydrogen (HI, HII), helium (HeI), oxygen (OI, OII, OIII), nitrogen (NI), magnesium (MgII), and sulfur (SII). The line intensities for weakly ionized atoms (such as neutral atomic oxygen, OI) are stronger than those of strongly ionized atoms (such as doubly ionized oxygen, OIII). A galactic nucleus with such spectral properties is termed a LINER, for "low-ionization nuclear emission-line region". The mechanism and source of weak-line-dominated ionization in LINERs and M87 are under debate. Possible causes include shock-induced excitation in the outer parts of the disk or photoionization in the inner region powered by the jet.

Elliptical galaxies such as M87 are believed to form as the result of one or more mergers of smaller galaxies. They generally contain relatively little cold interstellar gas (in comparison with spiral galaxies) and they are populated mostly by old stars, with little or no ongoing star formation. M87's elliptical shape is maintained by the random orbital motions of its constituent stars, in contrast to the more orderly rotational motions found in a spiral galaxy such as the Milky Way. Using the Very Large Telescope to study the motions of about 300 planetary nebulae, astronomers have determined that M87 absorbed a medium-sized star-forming spiral galaxy over the last billion years. This has resulted in the addition of some younger, bluer stars to M87. The distinctive spectral properties of the planetary nebulae allowed astronomers to discover a chevron-like structure in M87's halo which was produced by the incomplete phase-space mixing of a disrupted galaxy.

Components

Supermassive black hole M87*

The core of the galaxy contains a supermassive black hole (SMBH), designated M87*, whose mass is billions of times that of the Earth's Sun; estimates had ranged from (3.5±0.8)×10 M_☉ to (6.6±0.4)×10 M_☉, surpassed by 7.22+0.34
−0.40×10 M_☉ in 2016. In April 2019, the Event Horizon Telescope collaboration released measurements of the black hole's mass as (6.5 ± 0.2_stat ± 0.7_sys) × 10 M_☉. This is one of the highest known masses for such an object. A rotating disk of ionized gas surrounds the black hole, and is roughly perpendicular to the relativistic jet. The disk rotates at velocities of up to roughly 1,000 km/s (2,200,000 mph) and spans a maximum diameter of 25,000 AU (3.7 trillion km; 2.3 trillion mi). By comparison, Pluto averages 39 AU (5.8 billion km; 3.6 billion mi) from the Sun. Gas accretes onto the black hole at an estimated rate of one solar mass every ten years (about 90 Earth masses per day). The Schwarzschild radius of the black hole is 120 AU (18 billion kilometres; 11 billion miles). The diameter of the ring of emission, as seen from Earth, is 42 μas (microarcsecond). By comparison, the diameter of the core of M87 is 45" (as, arcsecond), and the size of M87 is 7.2' x 6.8' (am, arcminute).

A 2010 paper suggested that the black hole may be displaced from the galactic center by about seven parsecs (23 light-years). This was claimed to be in the opposite direction of the known jet, indicating acceleration of the black hole by it. Another suggestion was that the offset occurred during the merger of two supermassive black holes. However, a 2011 study did not find any statistically significant displacement, and a 2018 study of high-resolution images of M87 concluded that the apparent spatial offset was caused by temporal variations in the jet's brightness rather than a physical displacement of the black hole from the galaxy's center.

This black hole is the first to be imaged. Data to produce the image were taken in April 2017, the image was produced during 2018 and was published on 10 April 2019. The image shows the shadow of the black hole, surrounded by an asymmetric emission ring with a diameter of 690 AU (103 billion km; 64 billion mi). The shadow radius is 2.6 times that of the black hole's Schwarzschild radius. The asymmetry in the brightness of the ring is due to relativistic beaming, whereby material moving towards the observer at relativistic velocities appears brighter. The visible material around the black hole rotates mostly clockwise with respect to the observer, which due to the direction of the axis of rotation causes the bottom part of the emission region to have a component of velocity toward the observer. The rotation parameter was estimated at ${\displaystyle a=0.9\pm 0.1}$, corresponding to a rotation speed ≈ 0.4 c. This is consistent with the value of ${\displaystyle a=1.00\pm 0.15}$ obtained with the outflow method.

After the black hole had been imaged, it was named Pōwehi, a Hawaiian word meaning "the adorned fathomless dark creation", taken from the ancient creation chant Kumulipo.

On 24 March 2021, the Event Horizon Telescope collaboration revealed an unprecedented unique view of the M87 black hole shadow: how it looks in polarized light. Polarization is a powerful tool which allows astronomers to probe physics behind the image in more detail. Light polarization informs us about the strength and orientation of magnetic fields in the ring of light around the black hole shadow. Knowing those is essential to understand how M87's supermassive black hole is launching jets of magnetized plasma, which expand at relativistic speeds beyond the M87 galaxy.

On 14 April 2021, astronomers further reported that the M87 black hole and its surroundings were studied during Event Horizon Telescope 2017 observing run also by many multi-wavelength observatories from around the world.

In April 2023, a team developed a new principal-component interferometric modeling (PRIMO) technique to produce sharper image reconstructions from EHT data. They applied this to the original EHT observations of the M87 black hole, yielding a crisper final image and allowing closer testing of the alignment of observations to theory.

Jet

The relativistic jet of matter emerging from the core extends at least 1.5 kiloparsecs (5,000 light-years) from the nucleus and consists of matter ejected from a supermassive black hole. The jet is highly collimated, appearing constrained to an angle of 60° within 0.8 pc (2.6 light-years) of the core, to about 16° at two parsecs (6.5 light-years), and to 6–7° at twelve parsecs (39 light-years). Its base has the diameter of 5.5 ± 0.4 Schwarzschild radii, and is probably powered by a prograde accretion disk around the spinning supermassive black hole. The German-American astronomer Walter Baade found that light from the jet was plane polarized, which suggests that the energy is generated by the acceleration of electrons moving at relativistic velocities in a magnetic field. The total energy of these electrons is estimated at 5.1 × 10 ergs (5.1 × 10 joules or 3.2 × 10 eV). This is roughly 10 times the energy produced in the entire Milky Way in one second, which is estimated at 5 × 10 joules. The jet is surrounded by a lower-velocity non-relativistic component. There is evidence of a counter jet, but it remains unseen from the Earth due to relativistic beaming. The jet is precessing, causing the outflow to form a helical pattern out to 1.6 parsecs (5.2 light-years). Lobes of expelled matter extend out to 80 kiloparsecs (260,000 light-years).

In pictures taken by the Hubble Space Telescope in 1999, the motion of M87's jet was measured at four to six times the speed of light. This phenomenon, called superluminal motion, is an illusion caused by the relativistic velocity of the jet. The time interval between any two light pulses emitted by the jet is, as registered by the observer, less than the actual interval due to the relativistic speed of the jet moving in the direction of the observer. This results in perceived faster-than-light speeds, though the jet itself has a velocity of only 80–85% the speed of light. Detection of such motion is used to support the theory that quasars, BL Lacertae objects and radio galaxies may all be the same phenomenon, known as active galaxies, viewed from different perspectives. It is proposed that the nucleus of M87 is a BL Lacertae object (of lower luminosity than its surrounds) seen from a relatively large angle. Flux variations, characteristic of the BL Lacertae objects, have been observed in M87.

Observations indicate that the rate at which material is ejected from the supermassive black hole is variable. These variations produce pressure waves in the hot gas surrounding M87. The Chandra X-ray Observatory has detected loops and rings in the gas. Their distribution suggests that minor eruptions occur every few million years. One of the rings, caused by a major eruption, is a shock wave 26 kiloparsecs (85,000 light-years) in diameter around the black hole. Other features observed include narrow X-ray-emitting filaments up to 31 kiloparsecs (100,000 light-years) long, and a large cavity in the hot gas caused by a major eruption 70 million years ago. The regular eruptions prevent a huge reservoir of gas from cooling and forming stars, implying that M87's evolution may have been seriously affected, preventing it from becoming a large spiral galaxy.

M87 is a very strong source of gamma rays, the most energetic rays of the electromagnetic spectrum. Gamma rays emitted by M87 have been observed since the late 1990s. In 2006, using the High Energy Stereoscopic System Cherenkov telescopes, scientists measured the variations of the gamma ray flux coming from M87, and found that the flux changes over a matter of days. This short period indicates that the most likely source of the gamma rays is a supermassive black hole. In general, the smaller the diameter of the emission source, the faster the variation in flux.

A knot of matter in the jet (designated HST-1), about 65 parsecs (210 light-years) from the core, has been tracked by the Hubble Space Telescope and the Chandra X-ray Observatory. By 2006, the X-ray intensity of this knot had increased by a factor of 50 over a four-year period, while the X-ray emission has since been decaying in a variable manner.

The interaction of relativistic jets of plasma emanating from the core with the surrounding medium gives rise to radio lobes in active galaxies. The lobes occur in pairs and are often symmetrical. The two radio lobes of M87 together span about 80 kiloparsecs; the inner parts, extending up to 2 kiloparsecs, emit strongly at radio wavelengths. Two flows of material emerge from this region, one aligned with the jet itself and the other in the opposite direction. The flows are asymmetrical and deformed, implying that they encounter a dense intra-cluster medium. At greater distances, both flows diffuse into two lobes. The lobes are surrounded by a fainter halo of radio-emitting gas.

Interstellar medium

The space between the stars in M87 is filled with a diffuse interstellar medium of gas that has been chemically enriched by the elements ejected from stars as they passed beyond their main sequence lifetime. Carbon and nitrogen are continuously supplied by stars of intermediate mass as they pass through the asymptotic giant branch. The heavier elements from oxygen to iron are produced largely by supernova explosions within the galaxy. Of the heavy elements, about 60% were produced by core-collapse supernovae, while the remainder came from type Ia supernovae.

The distribution of oxygen is roughly uniform throughout, at about half of the solar value (i.e., oxygen abundance in the Sun), while iron distribution peaks near the center where it approaches the solar iron value. Since oxygen is produced mainly by core-collapse supernovae, which occur during the early stages of galaxies, and mostly in outer star-forming regions, the distribution of these elements suggests an early enrichment of the interstellar medium from core-collapse supernovae and a continuous contribution from type Ia supernovae throughout the history of M87. The contribution of elements from these sources was much lower than in the Milky Way.

Examination of M87 at far infrared wavelengths shows an excess emission at wavelengths longer than 25 μm. Normally, this may be an indication of thermal emission by warm dust. In the case of M87, the emission can be fully explained by synchrotron radiation from the jet; within the galaxy, silicate grains are expected to survive for no more than 46 million years because of the X-ray emission from the core. This dust may be destroyed by the hostile environment or expelled from the galaxy. The combined mass of dust in M87 is no more than 70,000 times the mass of the Sun. By comparison, the Milky Way's dust equals about a hundred million (10) solar masses.

Although M87 is an elliptical galaxy and therefore lacks the dust lanes of a spiral galaxy, optical filaments have been observed in it, which arise from gas falling towards the core. Emission probably comes from shock-induced excitation as the falling gas streams encounter X-rays from the core region. These filaments have an estimated mass of about 10,000 M_☉. Surrounding the galaxy is an extended corona with hot, low-density gas.

Globular clusters

M87 has an abnormally large population of globular clusters. A 2006 survey out to an angular distance of 25′ from the core estimates that there are 12,000 ± 800 globular clusters in orbit around M87, compared with 150–200 in and around the Milky Way. The clusters are similar in size distribution to those of the Milky Way, most having an effective radius of 1 to 6 parsecs. The size of the M87 clusters gradually increases with distance from the galactic center. Within a four-kiloparsec (13,000-light-year) radius of the core, the cluster metallicity—the abundance of elements other than hydrogen and helium—is about half the abundance in the Sun. Outside this radius, metallicity steadily declines as the cluster distance from the core increases. Clusters with low metallicity are somewhat larger than metal-rich clusters. In 2014, HVGC-1, the first hypervelocity globular cluster, was discovered escaping from M87 at 2,300 km/s. The escape of the cluster with such a high velocity was speculated to have been the result of a close encounter with, and subsequent gravitational kick from, a supermassive black hole binary.

Almost a hundred ultra-compact dwarfs have been identified in M87. They resemble globular clusters but have a diameter of ten parsecs (33 light-years) or more, much larger than the three-parsec (9.8-light-year) maximum of globular clusters. It is unclear whether they are dwarf galaxies captured by M87 or a new class of massive globular cluster.

Environment

M87 is near (or at) the center of the Virgo Cluster, a closely compacted structure of about 2,000 galaxies. This forms the core of the larger Virgo Supercluster, of which the Local Group (including the Milky Way) is an outlying member. It is organized into at least three distinct subsystems associated with the three large galaxies—M87, M49 and M86—with the core subgroup including M87 (Virgo A) and M49 (Virgo B). There is a preponderance of elliptical and S0 galaxies around M87. A chain of elliptical galaxies roughly aligns with the jet. In terms of mass, M87 is likely to be the largest, and coupled with centrality appears to be moving very little relative to the cluster as a whole. It is defined in one study as the cluster center. The cluster has a sparse gaseous medium that emits X-rays, lower in temperature toward the middle. The combined mass of the cluster is estimated to be 0.15 to 1.5 × 10 M_☉.

Measurements of the motion of those intracluster starburst ("planetary") nebulae between M87 and M86 suggest that the two galaxies are moving toward each other and that this may be their first encounter. M87 may have interacted with M84, as evidenced by the truncation of M87's outer halo by tidal interactions. The truncated halo may also have been caused by contraction due to an unseen mass falling into M87 from the rest of the cluster, which may be the hypothesized dark matter. A third possibility is that the halo's formation was truncated by early feedback from the active galactic nucleus.

See also

• List of Messier objects

Notes

1. Size quoted refers to the diameter directly measured by the 25.0 mag/arcsec isophote at the B-band. The galaxy has a much diffuse and extensive halo extending up to 300 kpc (980,000 ly).
2. "Local universe" is not a strictly defined term, but it is often taken as that part of the universe out to distances between about 50 million to a billion light-years.
3. Epsilon Virginis is at celestial coordinates α=13ʰ02ᵐ, δ=+10°57′; Denebola is at α=11ʰ49ᵐ, δ=+14°34′. The midpoint of the pair is at α=12ʰ16ᵐ, δ=12°45′. Compare to the coordinates of Messier 87: α=12ʰ31ᵐ, δ=+12°23′ .
4. This yields a distance of 16.4 ± 2.3 megaparsecs (53.5 ± 7.50 million light-years).
5. This yields a distance of 16.7 ± 0.9 megaparsecs (54.5 ± 2.94 million light-years).

References

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117. ^ Shi, Y.; Rieke, G.H.; Hines, D.C.; Gordon, K.D.; Egami, E. (2007). "Thermal and Nonthermal Infrared Emission from M87". The Astrophysical Journal. 655 (2): 781–789. arXiv:astro-ph/0610494. Bibcode:2007ApJ...655..781S. doi:10.1086/510188. S2CID 14424125.
118. ^ Baes, M.; et al. (July 2010). "The Herschel Virgo Cluster Survey. VI. The far-infrared view of M87". Astronomy and Astrophysics. 518: L53. arXiv:1005.3059. Bibcode:2010A&A...518L..53B. doi:10.1051/0004-6361/201014555. S2CID 27004145.
119. Clemens, M. S.; et al. (July 2010). "The Herschel Virgo Cluster Survey. III. A constraint on dust grain lifetime in early-type galaxies". Astronomy and Astrophysics. 518: L50. arXiv:1005.3056. Bibcode:2010A&A...518L..50C. doi:10.1051/0004-6361/201014533. S2CID 119280598.
120. Jones, M. H.; Lambourne, R. J.; Adams, D. J. (2004). An introduction to galaxies and cosmology. Cambridge University Press. p. 13. ISBN 978-0-521-54623-2.
121. ^ Ford, H.C.; Butcher, H. (October 1979). "The system of filaments in M87 – Evidence for matter falling into an active nucleus". Astrophysical Journal Supplement Series. 41: 147–172. Bibcode:1979ApJS...41..147F. doi:10.1086/190613.
122. ^ Harris, William E.; Harris, Gretchen L. H.; McLaughlin, Dean E. (May 1998). "M87, Globular Clusters, and Galactic Winds: Issues in Giant Galaxy Formation". The Astronomical Journal. 115 (5): 1801–1822. arXiv:astro-ph/9801214. Bibcode:1998AJ....115.1801H. doi:10.1086/300322. S2CID 119490384. The authors give a metallicity of:

     ${\displaystyle {\begin{smallmatrix}\left\ =\ -0.3\end{smallmatrix}}}$

     within a 3-kiloparsec radius of the galactic core.
123. Tamura, N.; Sharples, R.M.; Arimoto, N.; Onodera, M.; Ohta, K.; Yamada, Y. (2006). "A Subaru/Suprime-Cam wide-field survey of globular cluster populations around M87 – I. Observation, data analysis and luminosity function". Monthly Notices of the Royal Astronomical Society. 373 (2): 588–600. arXiv:astro-ph/0609067. Bibcode:2006MNRAS.373..588T. doi:10.1111/j.1365-2966.2006.11067.x. S2CID 15127905.
124. ^ Madrid, J.P.; Harris, W.E.; Blakeslee, J.P.; Gómez, M. (2009). "Structural Parameters of the Messier 87 Globular Clusters". The Astrophysical Journal. 705 (1): 237–244. arXiv:0909.0272. Bibcode:2009ApJ...705..237M. doi:10.1088/0004-637X/705/1/237. S2CID 15019649. See Fig. 6. for a plot of the effective cluster radius versus galactocentric distance.
125. Caldwell, N.; Strader, J.; Romanowsky, A.J.; Brodie, J.P.; Moore, B.; Diemand, J.; et al. (May 2014). "A globular cluster toward M87 with a radial velocity < −1000 km/s: The first hypervelocity cluster". The Astrophysical Journal Letters. 787 (1): L11. arXiv:1402.6319. Bibcode:2014ApJ...787L..11C. doi:10.1088/2041-8205/787/1/L11. S2CID 116929202.
126. Zhang, H.X.; Peng, E.W.; Côté, P.; Liu, C.; Ferrarese, L.; Cuillandre, J.-C.; et al. (March 2015). "The Next Generation Virgo Cluster Survey. VI. The kinematics of ultra-compact dwarfs and globular clusters in M87". The Astrophysical Journal. 802 (1): 30. arXiv:1501.03167. Bibcode:2015ApJ...802...30Z. doi:10.1088/0004-637X/802/1/30. S2CID 73517961.
127. ^ Côté, P.; et al. (July 2004). "The ACS Virgo Cluster Survey. I. Introduction to the survey". The Astrophysical Journal Supplement Series. 153 (1): 223–242. arXiv:astro-ph/0404138. Bibcode:2004ApJS..153..223C. doi:10.1086/421490. S2CID 18021414.
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External links

• Messier 87, SEDS Messier pages
• ESA/Hubble images of M87
• Messier 87 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
• Solar elemental abundances

v t e Constellation of Virgo
List of stars in Virgo
Stars	Bayer α (Spica) β (Zavijava) γ (Porrima) δ (Minelauva) ε (Vindemiatrix) ζ (Heze) η (Zaniah) θ ι (Syrma) κ (Kang) λ (Khambalia) μ ν ξ ο π ρ σ τ υ φ (Elgafar) χ ψ ω Flamsteed 4 (A) 6 (A) 7 (b) 10 11 12 13 14 16 (c) 17 20 21 (q) 25 (f) 27 28 31 (d) 32 (d) 33 34 35 37 38 39 41 44 (k) 46 48 49 50 53 54 55 56 57 58 59 (e) 61 62 63 64 65 66 68 (i) 69 70 71 72 73 74 (l) 75 76 (h) 77 78 (o) 80 81 82 (m) 83 84 85 86 87 88 89 90 (p) 92 94 95 96 97 103 104 106 108 109 110 1 Ser (M Ser) 2 Ser Variable R S W RS RT SS ST SW TW TY UU UV UW UY XX AG AH AL AW AX AZ BB BF BH BK CE CS CU CX DK DL DM DT EP EQ ET FF FG FL FO FS FT FW GL GK GR GW HS HT HU HV HW IM IN IP IQ IS IV LN NN NY OU PP PX QS QZ HR 4478 4484 4510 4533 4544 4580 4587 4591 4598 4613 4657 4722 4741 4770 4772 4805 4837 4856 4877 4896 4901 4935 4957 (g) 4959 4960 4986 5013 5014 5031 5033 5037 5053 5059 5078 5086 5106 (y) 5114 5178 5183 5205 5233 5258 5272 5275 5276 5277 5283 5307 5317 5322 5332 5341 5342 5344 5353 5368 5384 5392 5418 5424 5496 5536 5584 5631 HD 102195 (Flegetonte) 102329 104078 104755 106038 106252 106270 106315 106515 107148 107794 109271 112495 114783 116429 119130 122577 124973 125490 125612 126614 128563 130322 (Mönch) 133600 Other EC 14012-1446 G 64-12 Gliese 486 Gliese 514 HAT-P-26 HAT-P-27 HE 1219-0312 K2-19 K2-229 PG 1323-086 PG 1325+101 PSR B1257+12 (Lich) Qatar-2 Ross 128 SDSS J121209.31+013627.7 SDSS J1229+1122 ULAS J133553.45+113005.2 WASP-16 WASP-24 WASP-37 WASP-39 (Malmok) WASP-54 WASP-55 WASP-85 WASP-107 WASP-157 WD 1145+017 Wolf 485A Wolf 489
Exoplanets χ Virginis b 38 Virginis b 61 Virginis b c 70 Virginis b e Virginis b Gliese 536 b HD 102195 b (Lete) HD 106252 b HD 107148 b HD 114783 b HD 125612 b c d HD 126614 Ab HD 130322 b (Eiger) HR 5183 b K2-229b KELT-21b PSR B1257+12 A (Draugr) B (Poltergeist) C (Phobetor) Ross 128 b SDSS J1228+1040 b WASP-16b WASP-24b WASP-39b (Bocaprins) WASP-85 Ab WASP-107b WD 1145+017 b
Star clusters HVGC-1 Koposov 1 NGC 5634
Nebulae Abell 36
Galaxies	Messier 49 58 59 60 61 84 86 87 89 90 104 (Sombrero Galaxy) NGC 3776 3817 3818 3833 3843 3848 3849 3852 3863 3876 3907 3907B 3914 3915 3952 3976 3976A 3979 4006 4012 4029 4030 4043 4044 4045 4045A 4058 4063 4067 4073 4075 4077 4079 4082 4083 4107 4116 4119 4123 4129 4139 4164 4165 4168 4176 4178 4179 4180 4191 4193 4197 4200 4201 4202 4206 4207 4215 4216 4223 4224 4233 4234 4235 4240 4241 4246 4247 4249 4252 4255 4257 4259 4260 4261 4264 4266 4267 4268 4269 4270 4273 4276 4277 4279 4281 4282 4285 4287 4289 4292 4292A 4294 4296 4297 4299 4300 4301 4305 4306 4307 4309 4309A 4313 4316 4318 4320 4324 4325 4326 4330 4333 4334 4339 4341 4342 4343 4348 4351 4352 4353 4356 4360 4365 4366 4368 4370 4371 4376 4378 4380 4385 4387 4388 4390 4402 4403 4404 4410 4411 4412 4413 4415 4416 4417 4418 4420 4422 4423 4424 4425 4428 4429 4430 4431 4432 4433 4434 4436 4440 4442 4445 4451 4452 4453 4454 4457 4458 4461 4464 4465 4466 4467 4469 4470 4476 4478 4480 4482 4483 4484 4486A 4486B 4487 4488 4491 4492 4493 4496 4496B 4497 4503 4504 4517 4517A 4518 4518B 4519 4519A 4520 4522 4526 4527 4528 4531 4532 4533 4535 4535A 4536 4538 4541 4543 4544 4546 4550 4551 4564 4567 4568 4570 4576 4577 4578 4580 4581 4584 4586 4587 4588 4592 4593 4596 4597 4598 4599 4600 4602 4604 4606 4607 4608 4612 4620 4623 4626 4628 4629 4630 4632 4636 4637 4638 4639 4640 4640B 4641 4642 4643 4647 (Arp 116) 4653 4654 4658 4660 4663 4664 4666 4668 4671 4674 4678 4680 4682 4684 4688 4690 4691 4694 4697 4698 4699 4700 4701 4703 4705 4708 4713 4716 4717 4718 4720 4731 4731A 4733 4734 4739 4742 4746 4753 4754 4757 4759A 4760 4761 4762 4764 4765 4766 4770 4771 4772 4773 4775 4777 4778 4779 4780 4780A 4781 4784 4786 4790 4791 4795 4796 4799 4803 4808 4809 4810 4813 4818 4820 4822 4823 4825 4829 4830 4836 4838 4843 4845 4847 4855 4856 4862 4863 4866 4877 4878 4880 4885 4887 4888 4890 4897 4899 4900 4902 4904 4915 4918 4920 4924 4925 4928 4933 4933C 4939 4941 4942 4948 4948A 4951 4958 4969 4975 4981 4984 4989 4990 4991 4992 4995 4996 4997 4999 5006 5010 5013 5015 5017 5018 5019 5020 5022 5027 5028 5030 5031 5035 5036 5037 5038 5039 5044 5046 5047 5049 5050 5054 5058 5059 5060 5066 5068 5071 5072 5073 5075 5076 5077 5079 5080 5084 5087 5088 5094 5095 5097 5099 5104 5105 5106 5111 5115 5118 5119 5122 5125 5129 5130 5132 5133 5134 5136 5137 5146 5147 5148 5159 5165 5167 5170 5171 5174 5176 5177 5178 5179 5181 5183 5184 5185 5186 5191 5192 5196 5197 5202 5203 5207 5208 5209 5210 5211 5212 5213 5221 5222 5224 5226 5227 5230 5231 5232 5235 5241 5245 5246 5247 5252 5254 5261 5270 5285 5300 5306 5324 5327 5329 5331 5334 5335 5338 5339 5343 5345 5348 5356 5360 5363 5364 5366 5369 5373 5374 5382 5384 5386 5387 5392 5400 5420 5442 5468 5470 5472 5476 5478 5491A 5491B 5493 5496 5501 5506 5507 5510 5521 5534 5537 5549 5551 5552 5554 5555 5560 5563 5566 5569 5573 5574 5575 5576 5577 5584 5599 5604 5618 5619 5619C 5636 5638 5645 5652 5661 5668 5674 5679 5679A 5679C 5679D 5680 5690 5691 5692 5701 5705 5713 5718 5719 5725 5733 5738 5740 5746 5750 5765 5765B 5770 5774 5775 5776 5806 5811 5813 5814 5831 5838 5839 5845 5846 5846A 5847 5848 5850 5854 5855 5864 5865 5869 Other A1689-zD1 Abell 1835 IR1916 Arp 240 (NGC 5257 and NGC 5258) Arp 271 (NGC 5426 and NGC 5427) BR 1202-0725 3C 273 3C 279 3C 298 4C 04.42 Eyes Galaxies GR 8 IC 1011 IC 1101 IC 3078 IC 3258 IC 3328 IRAS 12212+0305 IRAS 13197−1627 LEDA 1245565 M60-UCD1 Markarian 50 Markarian 1318 PG 1216+069 PG 1244+026 PG 1254+047 PG 1307+085 PG 1416−129 PG 1426+015 PKS 1148-001 PKS 1167+014 PKS 1217+023 PKS 1229−021 PKS 1302−102 PKS 1335−127 PKS 1402-012 PKS 1402+044 PKS 1405−076 QSO B1208+1011 QSO B1243−072 QSO B1246−057 QSO B1331+170 RXJ1242−11 SMM J14011+0252 UM 448 UM 461 UM 462
Galaxy clusters Abell 1644 Abell 1650 Abell 1651 Abell 1689 Abell 1750 Abell 1835 Abell 2029 Abell 2147 HCG 62 IRAS 13218+0552 MKW 4 NGC 5044 group RX J1347.5−1145 Virgo Cluster
Astronomical events GRB 930131 GRB 030328 GRB 050408 GRB 050801 GRB 080310 North Polar Spur SN 1960F SN 1981B SN 1990B SN 1990N SN 1991T SN 1991bg SN 1994D SN 1999br SN 2002cx SN 2007bi SN 2020jfo U1.11
Category

v t e Messier objects
List	M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 M12 M13 M14 M15 M16 M17 M18 M19 M20 M21 M22 M23 M24 M25 M26 M27 M28 M29 M30 M31 M32 M33 M34 M35 M36 M37 M38 M39 M40 M41 M42 M43 M44 M45 M46 M47 M48 M49 M50 M51 M52 M53 M54 M55 M56 M57 M58 M59 M60 M61 M62 M63 M64 M65 M66 M67 M68 M69 M70 M71 M72 M73 M74 M75 M76 M77 M78 M79 M80 M81 M82 M83 M84 M85 M86 M87 M88 M89 M90 M91 M92 M93 M94 M95 M96 M97 M98 M99 M100 M101 M102 M103 Added M104 M105 M106 M107 M108 M109 M110
See also	Caldwell catalogue Catalogue of Nebulae and Clusters of Stars Herschel 400 Catalogue Index Catalogue New General Catalogue Revised New General Catalogue
Category Commons Portal

v t e 2019 in space
« 2018 2020 »
Space probe launches	Beresheet (lunar lander; Feb 2019) LightSail 2 (solar sail demonstration; Jun 2019) Chandrayaan-2 / Vikram / Pragyan (lunar obiter, lander and rover; Jul 2019)
Impact events	Kamchatka meteor (announced) 2019 MO
Selected NEOs	Asteroid close approaches 2018 XB4 2019 AS5 2016 AZ8 66391 Moshup 2019 OK 1620 Geographos 2006 QV89 2100 Ra-Shalom 2019 SU3 2019 TA7 2019 UN13
Exoplanets	AD Leonis b Beta Pictoris c DS Tucanae b Gliese 251 c Gliese 357 d Gliese 588 b c Gliese 687 c Gliese 555 b Gliese 754 b Gliese 784 b HR 5183 b Kepler-47d confirmed K2-288Bb L 1159-16 b c d LP 816-60 b LTT 1445 Ab Luyten's Star d e PDS 70c Proxima Centauri c Struve 2398 Bb Bc Tau Ceti i (hypothesized) Teegarden's Star b c V1298 Tauri b c d e Wolf 359 b c
Discoveries	2019 AQ3 ASASSN-19bt AT2019qiz GRB 190114C EPIC 204376071 GW190412 GW190521g (first-ever light from bh-bh merger) GW190814 (first-ever "mass-gap" collision) J043947.08+163415.7 K2-18b water vapor M87* imaged PSR J0030+0451 mapped PSR J0740+6620 S5-HVS1 2I/Borisov 20 moons of Saturn WD 0145+234 detection of exoasteroid disruption WD J0914+1914
Comets	C/2018 Y1 (Iwamoto) 78P/Gehrels 168P/Hergenrother 163P/NEAT 138P/Shoemaker–Levy 171P/Spahr 289P/Blanpain
Space exploration	New Horizons (encounter with 486958 Arrokoth; Dec 2018 / Jan 2019) Chang'e 4 / Yutu-2 (landing on the far side of the Moon; Jan 2019) Opportunity (end of mission; Aug 2018 / Feb 2019) Hayabusa2 (departure from 162173 Ryugu; Dec 2019)
Outer space portal Category:2018 in outer space — Category:2019 in outer space — Category:2020 in outer space

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