The transitional disk around the star LkCa 15 All of the light at this wavelength is emitted by cold dust in the disk. the hole in the center indicates an inner gap with radius of about 55 times the distance from the Earth to the Sun. Right: An expanded view of the central part of the cleared region, showing a composite of two reconstructed images (blue: 2.1 microns, from November 2010; red: 3.7 microns) for LkCa 15. The location of the central star is also marked. Photo: NASA | FlickrCC.
Young stars usually have disks of matter orbiting them, from which their planets form. As matter collides together and forms into large bits, those bits start to develop stronger gravity, attracting more bits, and so on.
Eventually you get a planet. But, of the almost 2,000 planets that we have confirmed outside of our own solar system, until recently we had never seen one that was forming.
Now, orbiting the stark LkCa 15, we’ve found just such a planet. The star in question is much like our own sun, but is a mere 2 million years old (our sun is 4.6 billion years old). It can be found in the Taurus constellation about 450 million light years away.
Researchers confirmed that there was a planet within LkCa’s disk and that it had several smaller sibling planets near it as well. What is really interesting though, is that they could also observe hydrogen being pulled from the disk to the planet.
So far though, they aren’t sure how that works. They also aren’t sure how it’s forming where it is, or why it’s still growing. But these are the kind of questions that they’re excited to ask.
This newly discovered star would allow scientists to put some of their ideas about how planets form to the test, allowing us to directly observe a growing planet. Luckily, that process takes an incredibly long time, so it’s not as if we’re going to miss it. Locating the planet, by using infrared light to detect the hydrogen gas “feeding lines,” may also prove to be a helpful tool in discovering other young planets.
Now that we know this is a process, which at least some planets go through, we can search for those telltale signs near other stars as well, and hopefully find other planets at other stages in the development.
