Researchers at the University of North Carolina (UNC) in Chapel Hill, United States, have discovered a planet that is 10 times the size of Earth and is the youngest transiting planet ever known. The discovery was reported in the scientific journal Nature last Wednesday (20).
The planet, called EAT-1bis approximately the size of and has an estimated age of 3 million years. For comparison’s sake, if Earth were a 50-year-old person, this planet would be a two-week-old baby.
The was done by a UNC-Chapel Hill graduate student, Madyson Barber, under the direction of Professor Andrew Mann. The work began as research for Barber’s thesis project in the Faculty of Arts and Sciences’ Physics and Astronomy department.
“I’ve been looking for new planets for a while, and it seemed like we weren’t finding anything,” says Barber in . “This was one of the first planets to come out of our pipeline. It still looks very strange. ‘Weird’ is the best word I have for it.”
To arrive at the discovery, the team of researchers — made up of eight other students — observed the light emitted by the . If the light dims, it could be a sign of a transiting planet.
“When we look for transits, we are looking at the brightness of the star over a period of time,” says Barber. “When the planet arrives in front of the star, we see a small drop in its brightness, because it is blocking part of the star. So we’re looking for these repeated dips in the light curve.”
However, young planets are more difficult to find due to the protoplanetary disks that form around stars in the first 5 to 10 million years of their life. These discs are thick and block the view of observers.
However, the star that TIDYE-1b orbits has a misaligned disk, which allowed the planet to be visible to researchers. The origin of this misalignment is still a mystery to astronomers.
A Carolina graduate student has discovered the youngest transiting planet ever.
Madyson Barber, Ph.D. student in the College of Arts and Sciences, found Jupiter-sized planet TIDYE-1b by observing the light emitted by the star it transits.
— UNC College of Arts and Sciences (@unccollege)
“Planets form in disks, and what you would expect is that the star, the planet and the disk are all lined up,” explains Mann. “The really strange thing about this system is that the planet has an orientation that agrees with the star, but the disk is way off. It’s something like 60 degrees or more of difference”, he adds. This is a fact that confuses experts, according to the professor.
There is still more to learn about TIDYE-1b and its origins and subsequent observations are being led by Barber, including a trip to the WM Keck Observatory in Hawaii. Mann and Barber are also proposing time with the James Webb Space Telescope — the largest in space.
For researchers, the discovery of the planet “proves that we can find young systems”. “Now we know we should look further, and if we can make a population of these young systems, then we can draw even more conclusions,” says Barber.
