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Monday 15 October 2012

Black Hole

A black hole is an object in space whose gravity is so great that nothing can escape from it, not even light. Black holes can be detected because gas falling towards them becomes so hot that it emits X-rays.

On April 10, 2019, astronomers released the first direct image of a supermassive black hole (see below), located at the center of the supergiant elliptical galaxy Messier 87 (M87) in the constellation Virgo. The black hole was imaged by the Event Horizon Telescope (EHT), a network of telescopes around the world that work together to create a virtual telescope the size of the Earth. The image showed a bright ring of light surrounding a dark central region, which corresponded to the event horizon of the black hole, the point of no return beyond which nothing can escape its gravitational pull. 

By Event Horizon Telescope - https://iopscience.iop.org/journal/2041-8205,

V Telescopii is a triple star system in the southern constellation of Telescopium, near the southern constellation boundary with Pavo. It is located at a distance of approximately 1120 light years from the Sun. A May 2020 study reported it to contain a black hole, making it the closest known black hole, and the first one located in a star system visible to the naked eye.

In 2023, astronomers using the Hubble Space Telescope discovered a supermassive black hole that is creating stars instead of just sucking them up. This is the first time that a black hole has been observed to be actively involved in star formation

The idea of black holes was first proposed in 1783 by Yorkshireman John Michell, calling them "dark stars" and proposing a method to detect them by looking for star systems that showed the gravitational effects of two stars, but only one star was visible, which is indeed how scientists look for them today.

The term black hole for a collapsed star was opposed by the French, as its literal translation into French is a rude term.

At the centre of our Galaxy lies an object that has a mass four million times that of the Sun and is almost certainly a black hole.

Black holes "spaghettify" any objects entering the black hole, stretching them out in a process called spaghettification. This is because the tidal forces inside a black hole are so strong that they stretch the object into a long thin noodle of its composite atoms as it descends.

Black holes don't suck up everything nearby—they sit dormant and if a star approaches it and gets too close, the black hole becomes active.

No matter how long you watch an object slip into a black hole, you will never actually see the object enter it due to time dilation.

If you were near a black hole and facing away from it, you could actually see the back of your own head due to the light bending.

A black hole the size of a hydrogen atom would exert a pull from 2,000 feet away.

Wikipedia

A black hole emits a deep b flat sound.

Over billions of years, black holes become white holes and they spit out all of the things they sucked in. the atoms are completely jumbled, so no one knows what will ever come out. 

The black hole inside RX J1131 was the first black hole to have its spin directly measured.

Sagittarius A, the supermassive black hole in the center of our galaxy has four million times the mass of the Sun, but a diameter only 31 times the Sun's. It is so dense that it could fit in the space between the Earth and the Sun, but can attract things 50,000 light years away.

The largest known black hole is in the Holmberg 15A supergiant elliptical galaxy It has a diameter of 1 trillion kilometers, more than 190 times the distance from the Sun to Pluto.

The supermassive black hole at the center of the quasar OJ287 has been measured as weighing 18 billion times the mass of the Sun, six times heavier than the previous record holder.

The merging of two black holes in 2015 emitted 3.6 septillion yottawatts of power, greater than the combined power of all light radiated by all the stars in the observable universe.

The research that went into creating the visual effects for the black hole in Christopher Nolan's 2014 movie Interstellar was very thorough and extensive. The visual effects team worked closely with theoretical physicist Kip Thorne, who served as a scientific consultant on the film. Thorne's work on the film's black hole effects led to the publication of three scientific papers that explore the physics of black holes and the appearance of a black hole as seen from a nearby observer.

Source Hutchinson Encyclopedia © RM 2012. Helicon Publishing is division of RM

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