Black Hole
A black hole is a region where gravity is so strong that, under certain conditions, nothing escapes. In Descienced it is a top comparison object for extremes, scales, and theory connections.
astronomy.black-holes
Metrics
Mass of Sagittarius A*
Supermassive black hole at the center of the Milky Way. Mass determined by stellar orbits (Nobel Prize 2020, Genzel/Ghez).
Event Horizon (Sagittarius A*)
Schwarzschild radius for ~4 million solar masses. Corresponds to about 17 solar radii.
Temperature (Hawking Radiation)
Hawking temperature is inversely proportional to mass. For Sagittarius A* it is about 10^-14 K — far below the cosmic microwave background.
Relations
Many descriptions of black holes are based on general relativity (context relation).
Explanations
A black hole is a region where gravity becomes so extreme that even light cannot escape from it. The most famous example is Sagittarius A* at the centre of our Milky Way: it has a mass of about 4 million suns and an event horizon (the boundary beyond which nothing can escape) of approximately 12 million kilometres in diameter. Black holes emerge from General Relativity and serve as extreme laboratories for testing our understanding of physics.
Sources
First image of Sgr A* published May 2022. Mass estimates consistent with Nobel-Prize-winning stellar orbit measurements.
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Provenance
Status
seed
Review
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Last Updated
2026-02-16