Giant planets around young stars: Time to recast concepts on planet formation?

Young star

A team of researchers at the University of Cambridge has identified a young star with four Jupiter and Saturn-sized planets orbiting around it. It should be noted that this is for the first time scientists have spotted so many massive planets in such a young system. Interestingly, the system also has the most extreme orbits ever discovered as the outermost planet in this young system is more than a thousand times further from the star when compared to the innermost one.

The new discovery is now raising very crucial questions regarding planetary formations in such young systems. In this case, the star is just two million years old, and in astronomical terms, it can be considered a mere toddler. The star is surrounded by a huge disc of dust and ice known as protoplanetary disc where bodies planets, moons, and asteroids form.

The study report published the Astrophysical Journal Letters revealed that the star CI Tau, is located about 500 light years away in a highly productive nursery in the galaxy. The closest planet orbiting the star is the so-called hot Jupiter. Researchers believe that only one percent of the stars host hot Jupiters, and most of the hot Jupiters are apparently hundred times older than CI Tau, the star toddler.

"It is currently impossible to say whether the extreme planetary architecture seen in CI Tau is common in hot Jupiter systems because the way that these sibling planets were detected—through their effect on the protoplanetary disc – would not work in older systems which no longer have a protoplanetary disc," said Cathy Clarke, a professor at the Cambridge's Institute of Astronomy.

Researchers are still unclear regarding the role the sibling planets have played in driving the hot Jupiter to the innermost orbit. The study team is now planning to do more analysis on this system at multiple wavelengths to get more vital clues about the properties of the star disc and its planets.