WASP 12b is located around a star 867 light years away from Earth in the constellation Auriga. It was discovered in 2008 and is currently the hottest known exoplanet, with a surface temperature of about 2,200°C (4,000°F). It is almost twice the size of Jupiter and orbits about 3.4 million kilometres out from its parent star; as the planet is so close to its star, the star’s gravity pulls it into a slight egg like shape. In contrast, Earth orbits about 150 million kilometres out from the sun. WASP-12b orbits its parent star once every Earth day.
On May 20, 2010, the Hubble Space Telescope spotted WASP-12b being consumed by its star. While scientists had been aware of such phenomena, this was the first time such an event had been observed so clearly. It is estimated that the planet has 10 million years left of its life. NASA's Spitzer Space Telescope discovered that WASP-12b has more carbon than oxygen, making it the first carbon-rich planet ever observed. As concentrated carbon can take the form of diamond, it is possible that carbon-rich gas planets could have abundant diamond in their interiors.
Also in 2010, scientists at the Open University found that WASP-12b's parent star dimmed at times when the exoplanet passed in front of the star as seen from Earth sooner in ultraviolet wavelengths than in optical wavelengths during transits. At the time the astronomers thought the signal was from a cloud of material being stripped away from the planet by the parent star. Astronomers inferred that the planet had a magnetosphere, based on observations using the Hubble Space Telescope.
In 2011, Aline Vidotto and Ph.D. student Joe Llama used computer simulations to see whether the planet might create compress the material in front of it to create a bowshock ahead of it, acting like a shield which protects it while it journeys through a supersonic headwind while orbiting so close to its parent star. The star that WASP-12b orbits is a yellow dwarf that spews out charged particles much like the sun's solar wind. The researchers simulated magnetic fields for the planet and then observed the interactions between the magnetic fields and the solar wind streaming from the nearby star.
Research such as this gives astronomers another tool with which to measure the strength of planetary magnetic fields. The team has been able to examine other exoplanets and found that their orbital conditions would allow a similar bowshock; bowshocks could be more common than previously thought.
The image is an artist’s impression of WASP-12b, showing the star's gravity pulling material off the planet into a disk around the star.
0 comments:
Post a Comment