For those who dream a day of interstellar travel, it is not really worth to imagine leaving to meet WASP-12b. This exoplanet is entirely black. One of the darkest planets in space that absorbs but reflects very little light from its star.
Using the Space Telescope Imaging Spectrograph (STIS) spectrometer from the Hubble Space Telescope , a team of astronomers from McGill University in Montreal, Canada and Exeter University of British Columbia measured WASP-12b as having a geometric albedo of 0.064.
A value of ” extremely low “, knowing that for comparison, this reflectivity is about 0.37 for the Earth, and 0.12 for our Moon (0.52 for Jupiter). The geometric albedo of WASP-12b was obtained by observing the exoplanet in October 2016, during an eclipse (behind its host star WASP-12).
“The results were surprising! The measured albedo of WASP-12b is 0.064 at most,” Bell said.
“This is an extremely low value, making the planet darker than fresh asphalt!”
This makes WASP-12b two times less reflective than our Moon which has an albedo of 0.12.
“We measured the optical geometric albedo of WASP-12b, which measures the light that is scattered back towards the source of light, and can have values above 1. This is in contrast to the Bond albedo, which describes the total amount of energy reflected across all wavelengths and always falls in the range of 0 to 1,” the researchers explained.
“The low albedo shows we still have a lot to learn about WASP-12b and other similar exoplanets,” Bell added.
Located at 871 light years from us, WASP-12b was discovered in 2008 (an announcement on April 1st …). Of Jupiter type hot, it gravitates very close to its star. It is thus locked by gravitational forces, and has fixed diurnal and nocturnal faces.
On its diurnal surface, the surface temperature of the exoplanet can reach 2600 ° C. This high temperature could be one of the explanations for so little reflected light.
Previously, scientists found that the unknown “Planet 9” was formed in the solar system.