Black Holes
35 questions tagged Black Holes — spanning every one of the seven Ws.
Why are there giant black holes at the centers of many galaxies?
Supermassive black holes likely grew over billions of years by swallowing gas, stars, and smaller black holes. Many galaxies also grew through mergers, which helped feed and enlarge their central black holes.
When was the first image of a black hole released?
The first image of a black hole was released on 10 April 2019. It showed the supermassive black hole in galaxy M87.
When was the first image of a black hole in the Milky Way released?
The first image of the Milky Way’s central black hole was released on 12 May 2022. It showed Sagittarius A* at the center of our galaxy.
When was the first supermassive black hole mass measured in a galaxy?
A pioneering black hole mass measurement was made in the late 1970s and early 1980s. It helped establish that galaxies can host supermassive black holes.
When was the first direct observation of a black hole released?
In April 2019, the Event Horizon Telescope released the first image of the black hole in M87.
When was the first image of the Milky Way’s central black hole released?
On 12 May 2022, astronomers released the first image of Sagittarius A*, the black hole at the center of the Milky Way.
Where is the supermassive black hole M87*?
M87* is at the center of galaxy Messier 87 in the Virgo Cluster. The galaxy is about 55 million light-years away.
Where was the first image of a black hole released from?
The first black hole image was released from observations of the galaxy M87 in 2019. The black hole is known as M87*.
Where is the first direct image of a black hole's surroundings centered on?
The Event Horizon Telescope’s famous black-hole image centered on M87*, the supermassive black hole in the galaxy Messier 87. M87 is in the Virgo Cluster, about 55 million light-years away.
Which supermassive black hole is one of the most massive directly measured?
One of the most massive directly measured supermassive black holes is in galaxy Holm 15A, with an estimated mass of tens of billions of suns. Such extreme objects sit at the centers of giant galaxies and grow through mergers and accretion.
Which black hole has the largest known event horizon diameter?
Among the largest known black holes, TON 618 is often cited as one of the most massive, with an estimated mass of tens of billions of Suns. A larger mass means a larger event horizon.
When was the first black hole candidate in a binary system discovered?
In the early 1970s, Cygnus X-1 became the first widely accepted black hole candidate in a binary system.
When was the first black hole imaged by the Event Horizon Telescope?
In 2019, the Event Horizon Telescope released the first image of a black hole, M87*.
Where is the nearest known black hole to Earth?
The nearest known black hole is in the Gaia BH1 system, about 1,560 light-years away in the constellation Ophiuchus.
Where is the event horizon of a black hole?
A black hole’s event horizon is the boundary around the black hole itself, where escape becomes impossible.
Which known black hole is the most massive?
One of the most massive well-studied black holes is in the quasar TON 618, with an estimated mass of about 66 billion Suns. The exact value is uncertain, but it is far larger than the black hole in the Milky Way.
Which supermassive black hole is closest to Earth?
The closest known supermassive black hole is Sagittarius A* at the center of the Milky Way, about 26,000 light-years away. It has a mass of roughly 4.3 million Suns.
Whose orbit was the first used to test Einstein’s general relativity around a black hole?
Andrea Ghez led observations of stars orbiting the Milky Way’s central black hole, especially the star S2. Her team used the orbit to test general relativity in a strong-gravity environment.
Whose calculations first predicted the existence of a black hole from stellar collapse?
Subrahmanyan Chandrasekhar’s work on stellar remnants led to the limit that bears his name and helped shape black-hole theory.
How do black holes grow without swallowing everything nearby?
They mainly grow by accreting gas, dust, and stars that get close enough, often through disks that feed material gradually. Many black holes also gain mass through mergers with other black holes.
Why do some galaxies have supermassive black holes at their centers?
Gas inflows, mergers, and repeated feeding over cosmic time can build black holes millions or billions of times the Sun’s mass. Many large galaxies, including the Milky Way, seem to host one.
What is the event horizon?
The event horizon is the boundary around a black hole beyond which nothing can escape, not even light. It marks the point of no return.
When was the first supermassive black hole measured in a galaxy?
The first strong evidence for a supermassive black hole in a galaxy came in the 1970s, especially through observations of M87 and other active galaxies.
When was the first image of a galaxy’s central black hole released?
The first image of a galaxy’s central black hole was released in April 2019 for M87*.
When was the first image of a black hole at the center of the Milky Way released?
The first image of Sagittarius A* was released in May 2022.
Where is Sagittarius A* located?
It is at the center of the Milky Way galaxy, in the constellation Sagittarius. The black hole has a mass of about 4 million Suns.
Where is the supermassive black hole M87* located?
It is in the center of the galaxy Messier 87 in the Virgo Cluster, about 55 million light-years away. Its shadow was the first black hole image ever released, in 2019.
Which black hole has the largest known mass?
TON 618 is one of the most massive black holes known, with an estimated mass of about 66 billion Suns. It is associated with a very distant quasar.
Which galaxy has the largest central black hole measured with strong evidence?
The galaxy Holm 15A is home to one of the most massive black holes measured directly, estimated at around 40 billion solar masses in some studies. It sits in the Abell 85 cluster.
Which galaxy contains the most studied supermassive black hole in the Milky Way’s neighborhood?
The Milky Way itself contains Sagittarius A*, the supermassive black hole at its center. It has a mass of about 4 million Suns and was imaged directly in 2022 by the Event Horizon Telescope.
Which galaxy was first identified as having a supermassive black hole at its core?
Many nearby active galaxies were among the first suspected black-hole hosts, but M87 became one of the clearest cases through decades of study. Its central black hole was the first ever imaged in 2019.
Whose work first proved that black holes could be a real astrophysical possibility?
John Michell proposed the idea of “dark stars” in 1783. He reasoned that gravity could be so strong that light could not escape.
Whose theory first predicted black holes as a mathematical possibility?
Karl Schwarzschild found an exact solution to Einstein’s equations in 1916 that implied the existence of black holes. The term “black hole” came much later.
How do black holes get weighed from far away?
Astronomers measure the motion of nearby stars or gas and use gravity to calculate the black hole’s mass. In some cases, they also use X-ray or radio observations of material orbiting the black hole.
How do astronomers find black hole centers in galaxies?
They track stars and gas moving very fast near the galactic center. Those speeds reveal an extremely massive, compact object, often millions or billions of times the Sun’s mass.