In an astronomical first, four gigantic planets have been detected around a very young star, a new study reports.
By Mike Wall | SPACE.com
The star in question is CI Tau, which lies about 500 light-years from Earth. CI Tau is just 2 million years old and is still surrounded by a swirling clump of dust and gas known as a protoplanetary disk.
The star was already known to host one planet, a world about 10 times more massive than Jupiter that circles CI Tau once every nine Earth days. This planet, called CI Tau b, was the first „hot Jupiter“ ever discovered around such a young star. [Gallery: The Strangest Alien Planets]
In the new study, a team of researchers observed CI Tau and its disk with the Atacama Large Millimeter/submillimeter Array (ALMA), a network of radio telescopes in the Chilean Andes. ALMA spotted three additional gaps in the disk, at distances of 13, 39 and 100 astronomical units (AU) from the star, the astronomers report. (One AU is the Earth-sun distance — about 93 million miles, or 150 million kilometers).
So it seems that CI Tau b has three siblings. And these newfound worlds are big, too: The team’s work suggests the innermost of the three is about as massive as Jupiter, while the outer two have Saturn-esque heft.
Astronomers had never spotted four gas-giant planets around such a young star before, study team members said. And the orbital range — the outermost planet lies about 1,000 times farther from CI Tau than the innermost world does — is extreme as well, the researchers added.