Extreme exoplanet is hot, dense… and doomed

Planet with six times the mass of Jupiter will be gone in 200 million years' time

A
a
-
The 2.2-metre telescope at Calar Alto Observatory that was used to study Kepler-432b

Credit: MPIA


By Russell Deeks

Two different teams of astronomers studying the exoplanet Kepler-432b have come to the same conclusion: it's a bit strange.

Kepler-432b was first detected, as the name suggests, by NASA's Kepler exoplanet-hunting satellite last year. It has since been studied more closely by two teams of astronomers, both based at Heidelberg University in Germany, with one group using the 2.2-metre telescope at Calar Alto Observatory in Spain and one using both the Calar Alto scope and the Nordic Optical Telescope in La Palma in the Canary Islands. And what they've discovered has led Dr Davide Gandolfi of the Königstahl Observatory - who was part of the team that first discovered the exoplanet - to call it "a real maverick".

Firstly, where most stars orbiting red giants like Kepler-432b's parent star have large, circular orbits, Kepler-432b's orbit is small and elliptical. Secondly, this unusual orbit means the planet experiences huge seasonal variations in temperature, from 500°C in the winter to 1,000°C in the summer. And thirdly, the planet is incredibly dense - it's about the size of Jupiter, yet has six times the mass.

"The days of Kepler-432b are numbered, though," said Mauricio Ortiz, a  PhD student at Heidelberg Centre for Astronomy who led one of the two studies. "In less than 200 million years, Kepler-432b will be swallowed by its continually expanding host star. This might be the reason why we do not find other planets like Kepler-432b -- astronomically speaking, their lives are extremely short."

Carousel image: Artist's impression of an exoplanet, NASA/ESA/C.Carreau  

Like this article? Why not:
ALMA sheds new light on starburst galaxies
previous news Article
MAVEN penetrates Mars’s inner atmosphere
next news Article
We use cookies to improve your experience of our website. Cookies perform functions like recognising you each time you visit and delivering advertising messages that are relevant to you. Read more here