Astronomers from the University of Arizona and Stanford University bore witness to a groundbreaking scientific discovery—a planet that was still undergoing the process of formation.
The new planet, named LkCa 15b, is around 450 light-years away from Earth and will be a Jupiter-like planet by the time it is finished forming. "It's an exciting observation," Stephanie Sallum from University of Arizona who led the research says, "now we can finally watch planetary formation as it's happening," which helps refine scientific research and better understand of how Earth was born.
While advancements in space technology have allowed us to discover more planets, this marks the first planet that can be observed as it forms. Scientists behind the discovery believe that we've never seen this because because planets spend only a brief period of their long lives in the formation stage and, thus, it would be highly unlikely for astronomers to come across a planet at the exact moment it forms. Another reason that we've never seen this may be the naturally gassy and dusty star systems where planets like LkCa 15 are located, making it hard to distinguish such an event and observe the process.
The research team used a combination of two types of astronomical observation methods, where infrared images of the LkCa 15 star system as seen through the Large Binocular Telescope in Arizona, with the precise measurements given by hydrogen-alpha emissions of the Megallan Telescopes in Chile. According to Sallum, combining the data from both telescopes led scientists to “unambiguously detect one planet.”
The researchers note how it was found, "The difference in brightness between a star and a young exoplanet is usually comparable to the difference between a firefly and a lighthouse. It’s very hard to isolate the light from the planet when it is so faint and so close to the star from our point of view. But, because we could focus on a special colour of light where the planet is glowing very brightly, the signal was significantly stronger than what we normally look for."
This discovery gives scientists an opportunity to understand the mechanics behind how planets can form from dust and gas. The new detection method used in this particular study may pave the way for further discovery of other still-forming worlds, after it has effectively demonstrated that it is a powerful and effective way to identify young planets.
“I was pretty excited as soon as I processed the data, but I wanted to be cautious,” said Kate Follette, a postdoctoral researcher at Stanford and co-lead author, in a press release. “I was pretty sure I had found something interesting, but in this field we’re always chasing objects that are just at the edge of what we can detect. The really cool thing is that it survived all of our tests to make sure it was real.”