Exoplanet "like a mirror" due to metallic clouds

LTT9779b, 280 light years from Earth, is a scorching Neptune-sized world whose metallic clouds cause it to shine like a mirror in space. Its albedo is as high as that of Venus despite being a very different world.

Like running hot water steams up a bathroom, a scorching stream of metal and silicate — the mineral of which glass is made — oversaturated LTT9779b's atmosphere until metallic clouds formed, he said.

These clouds "act like a mirror," reflecting away light, according to the European Space Agency's Cheops project scientist Maximilian Guenther. …

"It's a planet that shouldn't exist," Mr Parmentier said. "We expect planets like this to have their atmosphere blown away by their star, leaving behind bare rock."

There's more on the mysterious planet at the European Space Agency's Cheops site.

"Imagine a burning world, close to its star, with heavy clouds of metals floating aloft, raining down titanium droplets," says James Jenkins, astronomer at Diego Portales University and CATA (Santiago, Chile). James co-authored a scientific paper describing the new research, published in the journal Astronomy & Astrophysics today

Here's the paper, The extremely high albedo of LTT 9779 b revealed by CHEOPS.

The results found here in the optical when combined with those in the near-infrared provide the first steps toward understanding the atmospheric structure and physical processes of ultrahot Neptune worlds that inhabit the Neptune desert.

The what now?

The Neptunian Desert or sub-Jovian desert is broadly defined as the region close to a star (period < 2–4 days) where no Neptune-sized ( > 0.1 MJ) exoplanets are found. This zone receives strong irradiation from the star, meaning the planets cannot retain their gaseous atmospheres: They evaporate, leaving just a rocky core.

Neptune-sized planets should be easier to find in short-period orbits, and many sufficiently massive planets have been discovered with longer orbits from surveys such as CoRoT and Kepler. The physical mechanisms that result in the observed Neptunian Desert are currently unknown