Scientists have revealed (tiết lộ) the first ever photograph of a black hole!
Before now scientists have only ever predicted what a black hole would look like and all the “pictures” we’ve seen have been drawings from artists.
This new photograph was captured by the Event Horizon Telescope, which is actually made up of eight telescopes (kính viễn vọng) all over the world that connect together.
The black hole is 553 million light years (triệu năm ánh sáng) away from Earth in a galaxy we call Messier 87.
It is 40 billion kilometres wide which is three million times the size of Earth – no wonder scientists are describing it as “a monster”!
What is a black hole?
A black hole is usually formed from a dying star which collapses (vỡ vụn) in on itself.
All that matter (vật thể) gets packed together (tụ lại) into an incredibly small space with a really, really strong gravitational pull (trọng lực).
The pull is so strong that everything around it is sucked (hút, nuốt chửng) in and nothing can escape – not even light.
That’s why they’re called black holes.
While the black hole itself is invisible, we can see a ring around it.
That contains gas that is being heated, squeezed (bị siết, nén chặt) and pulled (lôi,cuốn vào) in a circle towards the centre of the black hole – kind of like water as it spins around a bath plug .
The gas in the ring around the black hole sends out (phát ra, truyền tín hiệu) really bright radio waves (song radio) as it falls into the hole.
In the photo, one section of the ring is brighter than the other because that’s the part that’s moving towards us.
How did they get the photo?
It wasn’t easy!
Black holes themselves are invisible (vô hình) so scientists have been searching for the shroud of gas and dust (lớp khí gas và bụi bao phủ) that surrounds them.
Dr Jessica Dempsey, the Deputy Director of the James Clerk Maxwell Telescope in Hawaii, says it’s amazing we got to see this one.
“This is some of the luckiest light in the universe. Instead of it getting sucked into the black hole, it’s being emitted (thải ra) just on the edge of (ngoài bờ rìa) the event horizon. And it’s lucky enough to get to us.”
Dr Dempsey was part of a team of more than 200 scientists that have been working for about 20 years to photograph a black hole using the Event Horizon Telescope.
It’s actually not a single telescope, but an array of (một chuỗi gồm) eight telescopes including the James Clerk Maxwell. There’s also another one in Hawaii, two in Chile, one in Arizona in the US, one in Spain, one in Mexico, and one right at the South Pole in Antarctica.
By combining the power of all those telescopes they created a virtual telescope (kính viễn vọng ảo) that was 9,000km in diameter, making it the world’s biggest camera.
In 2017 the array spent several nights pointed at the black hole, collecting heaps and heaps of (= a lot of) data.
There was so much information that it couldn’t be transferred over the internet so hundreds of hard drives had to be flown around the world so scientists could analyse it.
It took two years to piece the data together into the picture we see today.
So what happens next?
Well first of all, this discovery (công cuộc phát hiện) proves that black holes exist.
We already thought we did because we can see the effect they have on nearby stars and galaxies but we’d never actually seen one.
Now that we have, you can bet that many scientists will go hunting (săn lùng, truy tìm) for more.
It might not be that long before we see another photo of a black hole – this time one in our own galaxy.
Event Horizon has also been studying Sagittarius A which is a black hole right at the centre of the Milky Way (dải Ngân Hà) but the scientists are still processing the data (xử lý dữ liệu).
So stay tuned!