Dark Stars
Publishes a paper proposing that sufficiently massive stars could have escape velocities exceeding the speed of light, an important precursor to the black hole concept.
Astronomy topic guide · World History Database
History of Black Hole Astronomy
Black holes moved from theoretical possibility to observational astronomy over the twentieth and twenty-first centuries. Relativity supplied the conceptual framework, while observations of compact X-ray sources, quasars and stellar motions produced evidence for black holes across a huge range of masses. Gravitational-wave detections revealed merging stellar-mass black holes directly through spacetime itself. The Event Horizon Telescope then produced horizon-scale images of the supermassive black holes in M87 and at the centre of the Milky Way.
What this chronology covers
Evidence for black holes comes from several independent observational approaches. Astronomers infer compact objects from the motions of nearby stars or gas, detect high-energy radiation from accretion, observe quasars powered by supermassive black holes, measure gravitational waves from mergers and now resolve event-horizon-scale structures with very-long-baseline interferometry. This convergence of methods is central to understanding how a theoretical prediction became an observational field.
57matching astronomy records
2,423records in the complete astronomy database
Selected database timeline
The records below are drawn from the existing World History Database astronomy collection and arranged chronologically. For very broad subjects, the page shows a substantial selection rather than duplicating the entire parent database.
Black Holes
Laplace discusses bodies so massive that their escape velocity exceeds the speed of light, an early Newtonian precursor to the black-hole concept.
Schwarzschild Radius
The Schwarzschild solution, which makes use of Schwarzschild coordinates and the Schwarzschild metric, leads to the well-known Schwarzschild radius, which is the size of the event horizon of a non-rotating black hole
Gravitational Waves
Predicts gravitational waves as propagating disturbances in spacetime within general relativity.
Quadrupole Formula for Gravitational Waves
Refines gravitational-wave theory and derives the quadrupole form for radiated energy.
Black Holes
George David Birkhoff proves that the Schwarzschild spacetime geometry is the unique spherically symmetric solution of the Einstein vacuum field equations
On Gravitational Waves Published
Einstein and Rosen publish a corrected paper showing cylindrical gravitational-wave solutions.
Event Horizon
David Finkelstein identifies the Schwarzschild surface r = 2m [in geometrized units, i.e. 2Gm/c2, where r is the radius of the surface and m is the mass of the black hole] as an event horizon
Rapid Rotation of Andromeda Nucleus
Detects rapid rotation in the compact nucleus of M31 with colleagues, evidence later understood in the context of a massive central black hole.
Quasars
Schmidt identifies the redshift of quasar 3C 273, opening new relativistic astrophysics questions
Event Horizon
Roger Penrose proves that an imploding star will necessarily produce a singularity once it has formed an event horizon
Black Holes
Penrose proves that gravitational collapse can produce spacetime singularities, showing black-hole formation is a robust prediction of general relativity.
Nature of Quasi-Stellar Sources
Hoyle and Geoffrey Burbidge examined energetic models for quasars and their observed redshifts.
Quasar Line Spectra
Hoyle collaborated on interpreting the emission-line spectra of quasi-stellar objects.
Black Hole Area Theorem
Hawking proves that the area of a classical black-hole event horizon cannot decrease.
Binary Pulsar
Taylor studies the binary pulsar whose orbital decay later confirms energy loss by gravitational waves
Binary Pulsar
Hulse discovers a binary pulsar that provides an indirect test of gravitational wave emission
Binary Pulsar
Analyzes the binary pulsar whose orbital decay later confirms gravitational wave emission.
Sagittarius A Star Radio Source
With Robert Brown, discovers the compact radio source Sagittarius A* at the centre of the Milky Way.
Sagittarius A Star Radio Source
With Bruce Balick, discovers the compact Galactic Centre radio source Sagittarius A*, later associated with the Milky Way's central supermassive black hole.
First Gravitational Lens
Co-discovers Q0957+561, the first confirmed gravitationally lensed quasar.
NGC 4261 Black Hole Disk
Hubble reveals a disk of material in the core of NGC 4261 that appears to feed a massive central black hole.
M87 Massive Black Hole
Leads Hubble observations of rapidly orbiting gas in M87, providing strong evidence for a massive black hole at the galaxy's centre.
NGC 4258 Maser Disk
Maps water masers orbiting in a thin Keplerian disk in NGC 4258, providing compelling dynamical evidence for a massive central black hole.
Black Holes
Andrew Strominger and Cumrun Vafa use string theory to calculate the entropy of a black hole, getting the same answer as Hawking and Bekenstein
Black Holes
Andrew Strominger and Cumrun Vafa use string theory to calculate the entropy of a black hole, getting the same answer as Hawking and Bekenstein
M84 Black Hole Signature
Hubble spectroscopy maps rapidly moving gas in galaxy M84 and records a clear dynamical signature of a supermassive black hole.
Chandra Observes Andromeda Core
NASA's Chandra X-ray Observatory obtains a deep view of the M31 nucleus and surrounding X-ray sources, including emission near the central black hole position.
Missing Intergalactic Hydrogen
Hubble quasar spectroscopy reveals extensive filaments of ionized hydrogen between galaxies, helping account for matter missing from the nearby universe.
Sagittarius A Star X-Ray Flare
Leads Chandra observations detecting rapid X-ray flaring from Sagittarius A*, revealing activity from matter close to the Galactic Centre black hole.
Chandra Maps X-Ray Sources in Andromeda
Chandra results reveal numerous X-ray binaries in the central region of M31 and isolate an X-ray source consistent with the position of its supermassive black hole.
S2 Orbit Around Sagittarius A Star
His team tracks star S2 through a close orbit around Sagittarius A*, tightly constraining the compact mass at the Galactic Centre.
S0-2 Galactic Centre Orbit
Her team uses the orbit of S0-2 around the Galactic Centre to strengthen the case for a compact supermassive black hole.
S2 Spectroscopic Orbit
Uses precision spectroscopy and astrometry of S2 to improve measurements of the compact mass associated with Sagittarius A*.
Galactic Centre Stellar Orbits
Publishes high-precision stellar orbits around Sagittarius A*, refining the mass and distance of the Milky Way's central black hole.
Sagittarius A Star Proper Motion
Uses precision radio astrometry to constrain the motion of Sagittarius A*, supporting its identification with the Milky Way's central massive black hole.
GW170817 Kilonova
Tanvir leads Hubble observations of the optical counterpart to the neutron-star merger GW170817, linking gravitational waves with a kilonova.
Relativity, Theory of
Genzel observes gravitational redshift in the orbit of S2 near the Milky Ways central black hole
S2 Gravitational Redshift
As a leading GRAVITY scientist, helps measure gravitational redshift in S2 during its close passage around Sagittarius A*, testing general relativity near a supermassive black hole.
First Image of M87 Black Hole
As EHT project director, announces the first image of a black hole shadow, obtained from the supermassive black hole M87*.
M87 Black Hole Shadow
As EHT Science Council chair, helps lead the collaboration that reveals the first direct image of a black hole shadow in M87.
M87 Black Hole Imaging
Contributes imaging methods used by the Event Horizon Telescope collaboration to reconstruct the first black hole image from M87 data.
M87 Imaging Pipelines
Helps develop and validate independent imaging pipelines used to reconstruct the Event Horizon Telescope image of M87*.
AMIGA Maps Andromeda Circumgalactic Halo
Project AMIGA uses background quasars to map ionized gas around M31 in greater detail, showing a layered halo extending far beyond the visible stellar disk.
Nobel Prize for Galactic Centre Black Hole
Shares the Nobel Prize in Physics for discovering a supermassive compact object at the centre of the Milky Way.
Nobel Prize for Galactic Centre Black Hole
Shares the Nobel Prize in Physics for discovering a supermassive compact object at the centre of the Milky Way.
M87 Polarized Black Hole Image
Coordinates EHT polarimetry work revealing magnetic-field structure close to the event horizon of M87*.
M87 Polarization Analysis
Contributes calibration and polarization analysis for the Event Horizon Telescope view of magnetic fields near M87*.
DESI Main Survey Starts
Levi directs DESI as its five-year main survey begins mapping millions of galaxies and quasars to track the effect of dark energy across cosmic history.
First Image of Sagittarius A Star
As EHT project scientist, helps present the first direct image of Sagittarius A*, the supermassive black hole at the centre of the Milky Way.
Sagittarius A Star EHT Image
As EHT project director, helps lead the collaboration releasing the first image of the Milky Way's central black hole Sagittarius A*.
Sagittarius A Star Imaging
Contributes to Event Horizon Telescope imaging and interpretation of Sagittarius A* at event-horizon scales.
Sagittarius A Star Variability
Contributes to EHT analysis of rapid variability in Sagittarius A* while reconstructing its horizon-scale ring structure.
GN-z11 Early Black Hole
Leads JWST research identifying an actively accreting black hole in GN-z11 only about 400 million years after the Big Bang.
M87 2018 Black Hole Image
Leads analysis of independent 2018 EHT data that reproduces M87*'s ring and black hole shadow, confirming the feature's persistence.
Gaia BH3
Leads the discovery of Gaia BH3, a dormant roughly 33-solar-mass stellar black hole in the Milky Way identified through Gaia astrometry.
Omega Centauri Black Hole Evidence
Haberle leads Hubble stellar-motion measurements providing strong evidence for an intermediate-mass black hole in Omega Centauri.
Related astronomers
AryabhataProfile and database timelineBhaskara IIProfile and database timelineNicolaus CopernicusProfile and database timelineTycho BraheProfile and database timelineGalileo GalileiProfile and database timelineJohannes KeplerProfile and database timelineEdmond HalleyProfile and database timelineWilliam HerschelProfile and database timeline
Sources and editorial provenance
Compiled and edited by World History Database
Historical chronology compiled from the World History Database and checked against major scientific and historical reference sources.
Last reviewed: September 2026.
- Royal Museums Greenwich — History of astronomy
- Royal Museums Greenwich — History of the telescope
- NASA Science — Hubble timeline
- NASA Science — Exoplanet discovery history
- LIGO — GW150914 first gravitational-wave detection
- Event Horizon Telescope — first black-hole image
- NASA Webb — mission science and discoveries