M87* Black Hole
Reference data for the M87* supermassive black hole: 6.5 billion solar masses, 42-microarcsecond shadow diameter, and relativistic jet physics.
Provenance-Backed Scientific Measurements
Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Distance | 54800000 ly | ± 1600000 ly | Surface brightness fluctuation distance of 16.8 ± 0.8 Mpc adopted by the EHT Collaboration. | definitive | Event Horizon Telescope Collaboration Horizon-Scale Results |
| Black Hole Mass | 6500000000 M☉ | ± 700000000 M☉ | Event Horizon Telescope 1.3 mm shadow ring reconstruction (EHT Collaboration 2019). | definitive | Event Horizon Telescope Collaboration Horizon-Scale Results |
| Shadow Ring Diameter | 7e-7 arcmin | ± 5e-8 arcmin | Photon ring angular diameter of 42 ± 3 microarcseconds at 230 GHz. | definitive | Event Horizon Telescope Collaboration Horizon-Scale Results |
| Schwarzschild Radius | 128 AU | ± 14 AU | Event horizon radius for a non-spinning 6.5×10⁹ M☉ black hole (~19 billion km). | definitive | Event Horizon Telescope Collaboration Horizon-Scale Results |
| Bolometric Accretion Luminosity | 700000000 L☉ | ± 200000000 L☉ | Radiatively inefficient advection-dominated accretion flow (~2.7 × 10⁴² erg/s). | high-confidence | Event Horizon Telescope Collaboration Horizon-Scale Results |
| Host Systemic Velocity | 1284 km/s | ± 5 km/s | Standard astrophysical catalog determination | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots M87* Black Hole (Powehi) — First EHT Shadow at RA 12h 30m 49.42s, Dec +12° 23′ 28.0″ within Virgo, alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.
Astrophysical Context & Structure
On April 10, 2019, the Event Horizon Telescope (EHT) Collaboration unveiled the first direct horizon-scale image of a black hole: a glowing, crescent-shaped ring of 1.3-millimeter synchrotron emission surrounding the dark gravitational shadow of M87*, the supermassive black hole at the center of giant elliptical galaxy Messier 87 in Virgo. Synthesizing a virtual Earth-sized interferometer from eight millimeter-wave observatories across four continents, the EHT resolved a ring 42 ± 3 microarcseconds across—confirming Albert Einstein's general theory of relativity in the strong-field regime for a 6.5-billion-solar-mass compact object.
With a Schwarzschild radius of roughly 128 astronomical units (more than three times Pluto's average distance from the Sun), M87* dwarfs our entire planetary system. Its southern crescent appears brighter than the north because relativistic Doppler beaming amplifies emission from magnetized plasma swirling toward Earth at nearly the speed of light. Subsequent EHT polarization maps in 2021 and 86-GHz GMVA+ALMA imaging in 2023 traced ordered, spiraled magnetic field lines threading the accretion flow right down to the event horizon.
Through the Blandford-Znajek mechanism, the frame-dragging spin of the black hole twists those horizon-scale magnetic fields into a tightly collimated relativistic jet of electrons and positrons that erupts from the galactic core and extends over 5,000 light-years—a feature first spotted optically by Heber Curtis in 1918 as 'a curious straight ray' protruding from Messier 87.
Practical Visual Observing Guide
- While the 42-microarcsecond black hole shadow requires global millimeter VLBI, its host galaxy M87 (V = 8.6) is easily visible in small amateur telescopes in the Virgo Cluster.
- The 20-arcsecond optical relativistic jet launched by the black hole (V ~ 15) can be imaged with 8-inch+ amateur scopes and seen visually in 18-inch+ apertures under steady skies.
- Informally named 'Powehi' ('embellished dark source of unending creation') by Hawaiian language scholar Larry Kimura in collaboration with Hawaii EHT astronomers.
Catalog Cross-Identifications & Aliases
Common Aliases: Messier 87 Central Black Hole · Powehi · Virgo A Supermassive Black Hole
| Catalog Authority | Identifier |
|---|---|
| SIMBAD | Messier 87 Central Black Hole |
Related Objects, Comparisons & Guides
Messier 87 (Virgo A Giant Elliptical Galaxy)
Coordinates, distance (16.4 Mpc / 53.5 Mly), EHT 6.5-billion M☉ black hole M87*, relativistic jet, and observing guide for Messier 87.
Sagittarius A* (Galactic Center Black Hole)
Coordinates, GRAVITY S2 stellar orbit distance (8,277 pc) & mass (4.297 × 10^6 M☉), EHT 51.8 μas shadow, and Galactic Center guide for Sgr A*.
TON 618 — Ultramassive Black Hole & Quasar
Reference data for TON 618: redshift z = 2.219, ~40–66 billion solar mass black hole in Canes Venatici, and 140-trillion-solar-luminosity output.
Angular Size, Separation & Field of View
How angular diameter (degrees, arcminutes, arcseconds), spherical angular separation, and small-angle physical diameter relate to telescope field of view.
Measurement Uncertainty & Optics in Astronomy
How random vs systematic errors, asymmetric error bars, model dependencies, and optical aperture/exit-pupil limits shape astronomical measurements.
Scientific Sources & Dataset Provenance
- Event Horizon Telescope Collaboration Horizon-Scale Results (2019 ApJL 875 L1 & 2022 ApJL 930 L12): Event Horizon Telescope Collaboration 2019, ApJL, 875, L1; 2022, ApJL, 930, L12 — Event Horizon Telescope Collaboration
- SIMBAD Astronomical Database (CDS) (2026-10 release): Wenger, M., et al. 2000, A&AS, 143, 9 (The SIMBAD astronomical database) — Centre de Données astronomiques de Strasbourg