A supermassive black hole in our galaxy (the Milky Way) has been photographed. It’s called Sagittarius A* and it lies at the center of our galaxy.
How many black holes does the Milky Way have?
Somewhere between 10 million to 1 billion – that’s what scientists say. And that’s in our galaxy alone. The entire universe has some 100 billion (it is assumed)!
Back to Sagittarius A*
What’s this one about and who photographed it?
So, the image was captured by an international team called The Event Horizon Telescope Collaboration (EHT) – which comprises a network of telescopes from around the world that work together to capture images of the black hole.
How do telescopes around the world work together?
By a technique that links radio dishes across the earth to create an Earth-sized interferometer – an interferometer is an instrument that uses two beams of light to make measurements
The ring of light around the central dark region where the hole resides
is about 60 million km, or 40 million miles, across.
Source: Event Horizon Telescopes
Quick facts about Sagittarius A*
- It’s a supermassive black hole at the center of
- It’s 26,000 light-years away from the Earth (one light year is about 9.46 trillion kilometers!)
- It’s 4 million times the mass of the Sun
- Location in the universe: Center of our Milky Way galaxy
What’s a black hole?
A black hole is a place in space where the gravitational pull is so much that not even light can get out.
does this find of gravitational pull happen?
This usually happens when a very big star is dying. When a sat dies it falls in upon itself. Also, it is popularly believed by scientists that the smallest black holes were created when the universe began.
So, can you actually “see” a black hole?
Since light cannot escape a black hole, you can’t actually see one. They are invisible.
So how do you spot them.
With space telescopes. These have special tools that help in finding black holes.
How big are Black Holes?
There are two kinds – big and small. Many scientists believe that the smallest black holes are as small as just one atom. The big ones are called “stellar” black holes. The mass of these can go up to 20 times more than the mass of the sun.
Then there are the supermassive black holes…
Supermassive black holes have masses more than that of one million suns together!