Hubble spots stellar midwife unit pumping out baby planets
Young mother only 10 million years old appears to have twins
The Hubble Space Telescope has uncovered evidence of planets emerging from a disk of dust and gas surrounding a young star nearly 200 light years from our solar system.
A sequence of images taken in 2016 and 2021 show changes in the shadows surrounding a 10-million-year-old star which researchers suggest are signs of the early development of planets.
TW Hydrae is a pre-main-sequence star that is approximately 80 percent the mass and 111 percent the radius of the Sun. It is nestled about 196 light years from Earth in the constellation Hydra. As the system is tilted 90° from our line of sight, it gives astronomers a bird's eye view of the accumulation of matter around the star, which is 0.2 percent of the age of our Sun.
The set of images taken in 2016 uncovered shadows on the disks surrounding the young star, which scientists interpreted as an inner disk tilted relative to an outer disk, blocking the light from their host. One explanation researchers put forward is that a nascent planet caused the difference in disk alignment.
Images taken five years later are suggestive of the early development of more than one planet. They reveal a second shadow that emerged from yet another nested disk.
The findings were published in the Astrophysical Journal this week.
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John Debes, European Space Agency post-doctoral researcher at the Space Telescope Science Institute in Baltimore, was the lead author on the paper.
"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 told NASA.
The two shadows rotate around the star at different rates suggesting two unseen planets pulling dust into their orbits and creating differences in the system over just a few years.
"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 Debes.
The research team suggests the two planets may be the distance of Jupiter from the Sun. The orbital period of the shadows suggests such a distance. The inclinations of the disks – at 5-7° — is also comparable to our solar system.
"This is right in line with typical solar system style architecture," said Debes. ®