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Contents
What is the News?
Scientists from the Event Horizon Telescope(EHT) facility have revealed the first image of the black hole named Sagittarius A* at the centre of our galaxy i.e. the Milky Way.
What is Sagittarius A*(SgrA*)?
Sagittarius A* is a supermassive black hole at the center of our galaxy i.e. the Milky Way. It is located near the border of the constellations Sagittarius and Scorpius.
SgrA* possesses 4 million times the mass of our sun and is located about 26,000 light-years and 5.9 trillion miles (9.5 trillion km)—from Earth.
The diameter of Sagittarius A* is about 17 times that of the sun, meaning it would sit within the innermost planet Mercury’s solar orbit.
Is this the first-ever image of a black hole?
No. In 2019, the Event Horizon Telescope released the first-ever image of a black hole M87* – the black hole at the centre of another galaxy Messier 87 which is a supergiant elliptic galaxy.
How is Sagittarius A* different from M87*?
Imaging Sagittarius A* (SgrA*) was much more difficult than imaging M87* for the following reasons: 1) SgrA* is only one-thousandth the size of M87*, 2) the line of sight of SgrA* is obscured by a lot of matter and 3) variability of SgrA* makes it difficult to image.
What is Event Horizon?
Black holes are extraordinarily dense objects with gravity so strong that not even light can escape, making viewing them extremely challenging.
A black hole’s event horizon is the point of no return beyond which anything—stars, planets, gas, dust and all forms of electromagnetic radiation—gets dragged into oblivion.
What is an Event Horizon Telescope?
What is the significance of this discovery?
This image of the black hole referred to as Sagittarius A* (SgrA*) gave further support to the idea that the compact object at the centre of our galaxy is indeed a black hole. This discovery also strengthens Einstein’s general theory of relativity.
Source: The post is based on the following articles
“Astronomers reveal first image of black hole at the heart of Milky Way galaxy” published in Livemint on 13th May 2022.
“Event Horizon reveals true colours of SgrA*” published in The Hindu on 13th May 2022.
