March 26, 2019

20.06.10: The Low Down on WASP-12b.

A bizarre exo-world just got stranger in the past month, but not in the way many news outlets would have you believe. WASP-12b is destined for a short life, one that we many have been fortunate enough to catch it in the middle of. The story starts in 2008, with the transiting exoplanet’s discovery by the UKs Wide Area Search for Planets (WASP) array. The primary star, WASP-12, is a yellow dwarf located 600 light years distant in the constellation Auriga. Even at that time, it was known that WASP-12b was strange; it whizzed around its star in only 26 hours and had to be sizzling. Now, follow-up measurements with the Hubble Space Telescope and its newly installed Cosmic Origins Spectrograph have indeed revealed a world in peril; at 2800° degrees Fahrenheit, WASP-12b is bloated up to three times the radius of Jupiter, although it only contains 1.4 times its mass. COS was able to identify manganese, tin, and aluminum in the spectra of the atmosphere as the planet transited its host star, using its sensitivity in the ultraviolet to pin down key measurements such as its diameter. This would put the Roche Limit of the planet well beyond what its own gravity can retain. WASP-12b is more than likely feeding material to its stellar host, an act it can’t maintain forever. Calculations show that WASP-12b will cease to exist in about 10 million years or so.  It does, however, give astronomers an opportunity to gather a spectrum for study of a hot Jupiter in action… The WASP-12b story also fueled an avalanche of bad science stories, along the lines of “Cannibal Star 600 Million Light Years Distant Consumes Planet!” as if such a star bent on evil were inbound or headed our way. Never let the facts get in the way of a good story, guys… you keep us science news bloggers employed!