Black hole history
Humankind’s understanding of black holes has changed over time, as new observations and new theories exposed details of the mysterious dark objects. Explore these discoveries, including the new, first-ever image of the supermassive black hole at the Milky Way’s core, in the timeline below.
1939
STELLAR COLLAPSE
Robert Oppenheimer and Hartland Snyder describe how what we now call black holes could form as a massive star collapses under the weight of its own gravity.
The light from the star would become steadily fainter as it collapses: “The star thus tends to close itself off from any communication with a distant observer; only its gravitational field persists,” they wrote in Physical Review.
1963
QUASAR CONNECTION
Astronomer Maarten Schmidt discovers the first quasar when he realizes that what was thought to be an unusual star was an exceedingly bright, distant object .Scientists now know a quasar's brilliant light is produced by a huge disk of gas swirling around a gargantuan black hole.
The black hole, known as Sagittarius A*, appears as a faint silhouette amidst the glowing material that surrounds it. The image reveals the turbulent, twisting region immediately surrounding the black hole in new detail. A planet-spanning network of radio telescopes, known as the Event Horizon Telescope, worked together to create this much-anticipated look at the Milky Way’s giant .27,000 light-years away, the behemoth is the closest giant black hole to Earth. That proximity means that Sgr A* is the most-studied supermassive black hole in the universe. Sgr A* and others like it remain some of the most mysterious objects ever found.
That’s because, like all black holes, Sgr A* is an object so dense that its gravitational pull won’t let light escape. Black holes are natural keepers of their own secrets
That gas, drawn toward Sgr A* by its gravitational pull, flows into a surrounding disk of glowing material, called an accretion disk. The disk, the stars and an outer bubble of X-ray light “are like an ecosystem*
Sgr A ’s variability, the constant simmering, complicated the analysis because the black hole changes on timescales of just a few minutes, changing as the researchers were imaging it. Sgr A* feeds on hot material pushed off of massive stars at the galactic center. They’re completely tied together.
That accretion disk is where the action is — as the gas moves within immensely strong magnetic fields — so astronomers want to know more about how the disk works.
The black hole eats only a few morsels fed to it by its accretion disk. Still, “it’s always been a little bit of a puzzle why it’s so, so faint,”
Those “multiwavelength” data from the other telescopes were crucial to assembling the image.
By looking at these things simultaneously and all together, we’re able to come up with a complete picture .Ultimately, a better understanding of what is happening in the disk so close to Sgr A* could help scientists learn how many other similar supermassive black holes work.
Einstein’s steadfast theory of gravity passed: The size of the shadow matched the predictions of general relativity. By testing the theory in extreme conditions — like those around black holes — scientists hope to pinpoint any hidden weaknesses.
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