Researchers discovered a planet 1,400 light-years away that seems to “eat” the light coming from the sun-like star that it surrounds, whose name is WASP-12b. Astronomers reached to see the incredible hot WASP-12b exoplanet using the Hubble Space Telescope, which is “as dark as asphalt” according to them.

The exoplanet reflects most of its incoming light due to its unique ability to trap at least 94 percent of it, making the WASP-12b almost as dark as the entire space in front of any telescope. This study refutes any previous knowledge and gives the scientific community new evidence to change – or even create – a new hypothesis of WASP-12b’s atmosphere. This will help study another similarly sized exoplanets.

Artist's concept of hot Jupiter WASP-121. Image Credit: NASA
Artist’s concept of hot Jupiter WASP-121. Image Credit: NASA

Researchers from the McGill University, Canada, and the University of Exeter in the UK discovered the approximate amount of light that the planet reflects by using the Hubble Space Telescope, in the NASA/ESA Space Telescope Imaging Spectrograph (STIS). They called this amount of light as “the albedo.”

The WASP-12b was discovered in 2008. It’s also known as “hot Jupiter,” although its radius represents almost the double of Jupiter’s. It follows an orbit that’s very near to its host, making one year of the pitch-black planet year as long as one day in Earth. The very-short distance also stretches the shape of the exoplanet – making it look like an egg – and raises the temperature of its surface on the planet’s daylight side to 2,600 degrees Celsius.

“This new Hubble research further demonstrates the vast diversity among the strange population of hot Jupiters,” the lead researcher, Taylor Bell, said. “You can have planets like WASP-12b that are 4,600 degrees Fahrenheit and some that are 2,200 degrees Fahrenheit, and they’re both called hot Jupiters. Past observations of hot Jupiters indicate that the temperature difference between the day and night sides of the planet increases with hotter day sides. This previous research suggests that more heat is being pumped into the day side of the planet, but the processes, such as winds, that carry the heat to the night side of the planet don’t keep up the pace.”

The WASP-12b’s albedo

To determine the albedo of WASP-12b scientists studied the exoplanet during a 2016 eclipse where it was near full phase and passing behind its parent star.

The international experts found that the exoplanet’s albedo was 0.064 at most, making it nearly as dark as the asphalt. Compared with the moon, the WASP-12b is two times less likely to reflect the sun’s light, considering that the albedo of the moon is 0.12.

“We did not expect to find such a dark exoplanet,” said Taylor Bell from the McGill University and the Institute for Research on Exoplanets in Montreal, Quebec, Canada. “Most hot Jupiters reflect about 40 percent of starlight.”

Researchers also said that the albedo of the planet might increase the planet’s temperature because of the environment’s inability to create hot clouds, and the alkali metals that get ionized due to the boiling temperature of the planet’s daylight side.

The hydrogen molecules in the planet are broken down by the heat, converting them into atomic hydrogen that which leads WASP-12b’s atmosphere to be similar to a low-mass star.

Source: Astrophysical Journal