Only 33 years old, Katie Bouman has already participated in two huge scientific feats: After the unveiling of the first image of a black hole in 2019, she again played a key role in the unpublished image unveiled on Thursday, of the hole black placed. at the center of our own galaxy, called the Sagittarius A *.
A few years ago, she had become a world celebrity, invited as far as the US Congress. Now she’s a data processing specialist at Caltech University in California, and she’s still part of the huge international collaboration that made this achievement possible, the Event Horizon Telescope (EHT).
His working group is responsible for reconstructing a faithful photograph, from the gigantic mass of data collected by telescopes around the world.
AFP spoke to her shortly after the new image was unveiled.
– For you, the revelation of this second black hole image is less exciting than the first?
The first picture was spectacular, because it was the first time we could see a black hole. But I think the holy grail for the Event Horizon Telescope has always been to have a picture of Sagittarius A *.
For we have much more information about what Sgr A * should look like, via other scientific observations (eg the rotation of the stars around him, editor’s note). So being able to see a picture of it makes it much easier for us to compare whether it is what we expected, based on our previous observations and theories.
Therefore, I think that even though it is the second image we show, it is actually much more exciting because we can use it to further test our understanding of gravity.
– Why was it harder to get a picture of “our” black hole than of the M87 *, but still located much further away?
We both observed in the same week, in 2017. But it took us much longer to create the image of Sgr A * than for M87 *.
Many things make it much harder to get a picture of Sgr A *. First, we observe the black hole through the planet of our galaxy. Which means that the gas in the galaxy disturbs the image. A bit like looking through a frosted window, for example in a shower.
This is one of the challenges. But the hardest thing we had to face is that the black hole is developing very fast. The gas around M87 * and Sgr A * moves at about the same speed. But if it takes days or even weeks to drive around the M87 *, for Sgr A *, it develops every minute.
– Why do black holes fascinate us so much?
They break with what we know on Earth. Light cannot even escape them, and they distort the space-time around them. They are this mysterious thing and I think they capture our imagination.
What’s smarter than working on black holes? And to be able to take a picture of it, of something you should not be able to see … I think it’s fascinating.
– What are you most looking forward to in the future? The movie of a black hole?
I think this is only the beginning. Now that we have these extreme gravity labs, we can improve our instruments and our algorithms so we can see more of them and do more scientific experiments.
We have made a first attempt to get a film, and we have made great progress, but we are not at that point yet to be able to say, this is what Sgr A * looks like minute by minute. So we will try to add new telescopes in the world, collect more data so we can show something we know for sure.