Four super-Earth planets found around a single star

Four super-Earth planets found around a single star

Four rocky planets orbiting a star in Aquarius are among more than 100 new worlds found using the Kepler space telescope.

Led by astronomers at the University of Arizona, an international team used images taken by Kepler and telescopes in Hawaii to confirm the existence of 104 new planets, along with another 93 candidates.

Four super-Earth planets found around a single star

(Karen Teramura / Miloslav Druckmüller / Shadia Habbal / NASA)

Four planets not much bigger than Earth were found orbiting dwarf star K2-72, about 181 light years away in the Aquarius constellation. They orbit pretty close - nearer to their star than Mercury is to the sun - but are only subject to radiation and heat levels comparable to that on Earth.

Ian Crossfield of the University of Arizona's Lunar and Planetary Laboratory says the planets, with orbits between five and 24 days, could even harbour life.

The new findings come after a malfunction in 2013 forced the Kepler team to change how the telescope looked for stars - rather than focus on a small patch in the sky, it now looks more generally at a wider area, catching more cooler, red dwarf-style stars in its sights.

"Kepler's original mission observed a small patch of sky as it was designed to conduct a demographic survey of the different types of planets," said Prof Crossfield.

"This approach effectively meant that relatively few of the brightest, closest red dwarfs were included in Kepler's survey." 

This has allowed Kepler to pick "out a few gems for first study by the James Webb Space Telescope, which could perhaps provide information about their atmospheres", says Steve Howell, scientist at NASA's Ames Research Center in California.

The US$8 billion James Webb Space Telescope will launch in 2018.