This ‘insane’ planet is so hot its atmosphere is made of vaporised titanium and iron
‘Even though it is a planet it has the atmosphere of a star’
New observations of the hottest known planet have revealed temperatures similar to those typically seen at the surface of a star, as well as an atmosphere of vaporised iron and titanium.
The findings add to the diverse and, in some cases, extreme conditions seen on planets far beyond our own solar system.
Kevin Heng, a professor at the University of Bern, who led the latest work, said: “The temperatures are so insane that even though it is a planet it has the atmosphere of a star.”
“The main lesson that exoplanets are teaching us is that we can’t just look in the solar system,” Heng added. “There are really weird things out there.”
The planet, called Kelt-9b, was discovered last year by an American team. It is in orbit about a star 650 light years from Earth in the constellation of Cygnus, the swan. The ultra hot planet’s distance from its host star is one 30th that between the Earth is to the sun – and its star is also twice as hot as our sun. As a result, temperatures on Kelt-9b reach 4,000 degrees Celsius on the side that faces the star. This is not as hot as our sun, which is almost 6,000 degrees Celsius, but hotter than many stars.
The main lesson that exoplanets are teaching us is that we can’t just look in the solar system. There are really weird things out there
Due to its proximity to the star, the planet orbits the star every 36 hours, with the same side always facing inward. This means there is constant daytime on one side and constant night on the other, creating extreme temperature variations across the planet. The temperature of the night side is probably still about 2,000 degrees Celsius, though, Heng suggested.