'Mirror, mirror in the space': Stargazers stumble on fairytalish planet in Milky Way

 

In yet another remarkable discovery by astronomers, scientists have detected a new light-reflecting hot planet which is orbiting its sun-like star and is bigger than the size of Neptune.

The scientists said that the new planet, LTT9779b and its star are located in our Milky Way galaxy about 264 light years from Earth. It is covered with the metallic clouds made of titanium and silicates.

A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).

"It's a giant mirror in space," said a co-author and an astronomer James Jenkins of Diego Portales University and the Center for Excellence in Astrophysics and Associated Technologies (CATA) in Chile.

According to the research published in the journal Astronomy & Astrophysics, the planet reflects about 80% of incoming light, making it the universe's most reflective object ever known by the experts.

Our solar system’s most reflective object is Venus which is the brightest in Earth's night sky besides the moon, which is wrapped in toxic sulfuric acid clouds. It reflects about 75% of its light, whereas Earth reflects about 30%.

The planet's diameter is about 4.7 times greater than Earth, and it orbits very close to its star, even closer than Mercury's distance to the sun and 60 times closer than Earth's orbit.

Due to radiation, the newly discovered planet has surface temperature of 3,270 degrees Fahrenheit (1,800 degrees Celsius), hotter than molten lava.

Researchers said that with its star so close, it is a wonder it has any atmosphere.

"We even think that the clouds could condense into droplets, and have titanium rain falling in parts of the atmosphere," Jenkins said.

The researchers studied the planet using the European Space Agency's CHEOPS orbiting telescope.

"No other planet like this has been discovered to date," said astronomer and study lead author Sergio Hoyer of the Marseille Astrophysics Laboratory in France.

Possessing an atmosphere while orbiting so close to its star makes it "a planet that shouldn't exist," said study co-author Vivien Parmentier of the Côte d'Azur Observatory in France.

"The super-reflective cloud cover likely helped stop the planet from warming up too much and being stripped of its atmosphere," Parmentier said.

"This is quite unique as all other planets at this temperature that are big enough to keep their atmosphere are too hot to form clouds and are thus as dark as charcoal."

It also appears to be tidally locked to its star like the moon is to Earth, with a permanent day side facing the star and a permanent night side facing away.

All previously known planets that orbit their stars in less than one Earth day were either "hot Jupiters," gas giants similar in composition to our solar system's largest planet but much hotter due to solar radiation, or rocky planets smaller than Earth and lacking an atmosphere.

The researchers are pondering whether LTT9779b, classified as an "ultra-hot Neptune," perhaps began as a gas giant only to lose most of its atmosphere, or whether it started out at its current size.

So far, more than 5,000 planets outside of our solar system have been discovered, with traits vastly different than our solar system's eight planets. 

More discoveries are in line as sophisticated modern instruments are under construction and some like James Webb Space Telescope have gone operational last year.

"The diversity of exoplanets is stunning," Parmentier said, "and we have just scratched the surface."