Three ‘super-Earths’ among haul of 15 new planets discovered

13 Mar 2018

Illustration of another super-Earth-like planet, Kepler-62f, located 1,200 light years away. Image: NASA Ames/JPL-Caltech/Tim Pyle

A planet significantly bigger than our own that could harbour liquid water is among 15 planets recently discovered in deep space.

The rate at which our telescopes can identify new planets in deep space has increased exponentially, thanks to new technologies and scientific understanding. Now, we can add more than two dozen to our list of known exoplanets.

The discovery of 15 new planets was announced by a research team from the Tokyo Institute of Technology’s Department of Earth and Planetary Sciences, and it includes three so-called ‘super-Earths’.

One in particular has caught the attention of the researchers, as the planet dubbed K2-155d has a radius 1.6 times that of Earth and falls within the ‘Goldilocks zone’, whereby the planet could be habitable in its red dwarf star system located 200 light years away.

Based on 3D climate simulations obtained by NASA’s K2 space telescope and follow-up observations on the ground, the planet could potentially have liquid water on its surface.

However, before this could be confirmed, more precise estimates of the planet’s radius and temperature would need to be gathered, with help from interferometric techniques.

Aside from the discovery of a possible super-Earth, the research found that planets orbiting red dwarfs – small, cool and abundant stars – could have very similar characteristics to planets orbiting stars that resemble our own sun.

‘Very exciting targets’

“It’s important to note that the number of planets around red dwarfs is much smaller than the number around solar-type stars,” said Teruyuki Hirano, who led the research.

“Red dwarf systems, especially coolest red dwarfs, are just beginning to be investigated, so they are very exciting targets for future exoplanet research.”

The research also investigated the relationship between planet radius and the metallicity of the host star.

“Large planets are only discovered around metal-rich stars,” Hirano said, “and what we found was consistent with our predictions.

“The few planets with a radius about three times that of Earth were found orbiting the most metal-rich red dwarfs.”

Hirano and his team’s research has been featured in two papers published in The Astronomical Journal, and can be found here and here.

Colm Gorey was a senior journalist with Silicon Republic