New Exoplanet - WASP-18b

WASP-18b as visualized in Celestia.

When first discovered, "Hot Jupiters", giant exoplanets that orbited their stars more closely than Mercury orbits the Sun, were a source of amazement. 373 planets and 149 Hot Jupiters later close orbiting planets are a bit ho-hum.

Not so WASP-18b. Discovered by the Wide Angle Search for Planets, this amazing planet screams around its sun, HD 10069, in just under an Earth day. From WASP-18b's surface HD 10069 would occupy 30% of its sky (if you could see the sky from its surface). At over 7 times more dense than Jupiter, it probably has a large rocky core.

But it is so massive, and so close to its sun that WASP-18b that it should raise a tidal bulge on its sun, which should slow the planet down and make it spiral into its sun.

And there's the rub. WASP-18b should come close enough to HD 10069 to be torn apart in around 650,000 years. The likelihood that we would come across a planet so close to its death dive is quite remote, either we have been extraordinarily lucky in coming across WASP-18b, or there is something wrong with our theories of tidal dissipation in extrasolar systems. Either way, WASP-18b is a planet that will keep astronomers talking for some time.

Other discussions of WASP-18b at Sky and Telescope and ScienceNow!

If you want to add WASP-18b to Celestia, cut and paste the parameters below to a file and save it as WASP18b.ssc it the extras folder of Celestia, or download WASP18b.ssc to the extras folder.