Skip to main content

Hubble Observes Exoplanet that Snows Sunscreen


This is an artist’s impression of the exoplanet Kepler-13Ab as compared in size to several of the planets in the Solar System. The behemoth exoplanet is six times more massive than Jupiter. Kepler-13Ab is also one of the hottest known planets, with a dayside temperature of about 2700 °C. It orbits very close to the star Kepler-13A, which lies at a distance of 1730 light-years from Earth. Credit: NASA, ESA, and A. Feild (STScI)

Nighttime Titanium Oxide Snow Leaves Dayside Cloud-Free and Cooler


Travelers to the nightside of exoplanet Kepler-13Ab should pack an umbrella because they will be pelted with precipitation. But it's not the kind of watery precipitation that falls on Earth. On this alien world, the precipitation is in the form of sunscreen.

Ironically, the sunscreen (titanium oxide) is not needed on this side of the planet because it never receives any sunlight. But bottling up some sunlight protection is a good idea if travelers plan on visiting the sizzling hot, permanent dayside, which always faces its star. Visitors won't find any desperately needed sunscreen on this part of the planet.

Astronomers didn't detect the titanium oxide directly. They used Hubble to find that the atmospheric temperature grows increasingly colder with altitude on Kepler-13Ab, which was contrary to what they had expected. If titanium oxide were in the daytime atmosphere, it would absorb light and heat the upper atmosphere. Instead, high winds carry the titanium oxide around to the permanently dark side of the planet where it condenses to form clouds and precipitation. The planet's crushing gravity pulls all the titanium oxide so far down it can't be recycled back into the upper atmosphere on the daytime side.

The Hubble observations represent the first time astronomers have detected this precipitation process, called a "cold trap," on an exoplanet.

Kepler-13Ab is one of the hottest known planets, with a dayside temperature of nearly 5,000 degrees Fahrenheit. The Kepler-13 system resides 1,730 light-years from Earth.

Credits

Artwork: NASA, ESA, and G. Bacon (STScI) 
Science: NASA, ESA, and T. Beatty (Pennsylvania State University)

Resources

Hubble Observes Exoplanet that Snows Sunscreen 

Next Post


Scientists detect comets outside our solar system 

Etichette:

Comments

Post a Comment

Popular posts from this blog

A Sapphire Super-Earth

Twenty-one light years away, in the constellation Cassiopeia, a planet by the name of HD219134 b orbits its star with a year that is just three days long. With a mass almost five times that of Earth, it is what is known as a super-Earth. Unlike our planet, however, these super-Earths were formed at high temperatures close to their host star and contain high quantities of calcium, aluminum and their oxides – including sapphire and ruby. HD219134 b is one of three candidates likely to belong to a new, exotic class of exoplanets. These objects are completely different from the majority of Earth-like planets. They have 10 to 20 percent lower densities than Earth. Researchers looked at different scenarios to explain the observed densities. For example, a thick atmosphere could lead to a lower overall density. But two of the exoplanets studied, 55 Cancri e and WASP-47 e, orbit their star so closely that their surface temperature is almost 3,000 degrees and they would have lost this ...
Post a Comment
Read more

GAMMA-RAY EMISSION FROM THE SNR HB3

Image: At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded. Credit: NASA/CXC/SAO The processes of particles acceleration to very high energies from the supernova shock region and diffusion in the interstellar medium of such particles has not been well understood so far. Gamma-ray observations in the GeV regime are a powerful probe of these mechanisms
Post a Comment
Read more

Contributions to Cosmic Reionization from Dark Matter Annihilation and Decay

Image: A Schematic Outline of the Cosmic History - Credit: NASA/WMAP Science Team The epoch of reionisation and the emergence of the universe from the cosmic dark ages is a subject of intense study in modern cosmology.
Post a Comment
Read more