Exoplanet Discovered to be Orbiting to its Death

Melanie Rovinsky

Astronomers believe that planet WASP-18b, an incredibly massive and fiery “hot Jupiter,” will collide into the star it orbits in approximately one million years.

An artist's endering of an exoplanet
An artist's endering of an exoplanet

The exoplanet (a planet orbiting a star other than the sun) is causing plasma tides on its star because of its massive size and close orbit. According to Seth Borenstein, AP Science Writer, the planet’s star, WASP-18, is only 1.9 million miles from the planet – just about 1/50th of the distance between Earth and the sun. These tides are distorting the planet’s orbit and will eventually cause WASP-18b to collide with its star.

Coel Hellier, professor of astrophysics at Keele University, discovered the planet with help from the Wide Angle Search for Planets team (WASP). Both the star and planet were named after the group.

WASP-18b is nearly 10 times the mass of Jupiter and orbits its star in just 22 ½ hours. Sky & Telescope magazine claims that whereas Earth’s days are getting slightly longer (not noticeable at 0.2 seconds per century), WASP-18b’s days are getting shorter as the planet spirals inward at a faster and faster rate.

Astronomers will continue to watch and study the planet for changes confirming its suicidal nature. Astronomer Douglas Hamilton from the University of Maryland believes that within a decade it will be apparent whether or not WASP-18b is truly spiraling toward its death.