Astronomers are calling the planet LkCa 15 b, and say it is only two million years old (pretty small fry when compared with the Earth's 4 and a half billion years). Michael Ireland from Macquarie University, NSW, has imaged the planet's formation in partnership with Adam Kraus from the University of Hawaii.

Kraus says the discovery is the youngest exoplanet by far.

“LkCa 15 b is the youngest planet ever found, about 5 times younger than the previous record holder,” Mr Kraus said in a Keck Observatory press release.

“This young gas giant is being built out of the dust and gas. In the past, you couldn’t measure this kind of phenomenon because it’s happening so close to the star. But, for the first time, we've been able to directly measure the planet itself as well as the dusty matter around it.”

Capturing this picture was quite complex, involving coupling the adaptive optics of the Keck telescopes with aperture mask interferometry. Adaptive optics involves reducing distortions in space images caused by turbulence in our atmosphere. As light travels through the atmospheric layers of Earth, it can be bent or distorted by variances in the temperature of the atmosphere changing the refractive index of the light travelling through it. What this results in is twinkling, indistinct or distorted images.

The Keck telescopes correct this with adaptive optics which involves the use of a deformable mirror to compensate for detected variations in the light wavefronts coming to Earth. The mirror can change shape two thousand times a second. The effect of distorted images hitting a complimenting deformed mirror is clear images. Keck makes this image even clearer through use of aperture mask interferometry, where a mask is placed over the telescope with small holes in it, so less “noisy”, clearer images get through to the telescope for higher resolution.

[Wired]