Astronomers have spotted two shadows - believed to be a planet-forming exercise - around 200 light years away from Earth. The two shadows were discovered in a disk of gas and dust surrounding TW Hydrae after astronomers analysed its photo clicked by NASA's Hubble Space Telescope. Talking about the discovery, the American space agency said that TW Hydrae is a red dwarf star less than 10 million years old. Red dwarfs are the smallest - less than half the mass of the Sun - and the most common type of star in the Milky Way.
While the first shadow was spotted in 2017, the second appeared four years later, NASA said on its website.
The researchers said the findings, published in The Astrophysical Journal, give insight onto how Earth and other planets in the solar system may have looked when they were forming about 4.6 billion years ago.
The John Debes, an astronomer at the Space Telescope Science Institute in the US, said in the study: "We found out that the shadow had done something completely different."
"When I first looked at the data, I thought something had gone wrong with the observation because it wasn't what I was expecting. I was flummoxed at first, and all my collaborators were like: what is going on? We really had to scratch our heads and it took us a while to actually figure out an explanation," he added.
The team of researchers initially thought the shadows are being cast by two misaligned disks casting shadows. They were so close to each other in the earlier observation they were missed.
They later realised that the misaligned disks are likely caused by the gravitational pull of two planets in slightly different orbital planes.
"It does suggest that the two planets have to be fairly close to each other. If one was moving much faster than the other, this would have been noticed in earlier observations. It's like two race cars that are close to each other, but one slowly overtakes and laps the other," said Mr Debes.
Scientists now say that Hubble successor - the James Webb Space Telescope - may also be able to show the shadows in more detail because of its infrared vision.
