Advertisement

New GRAVITY instrument uses optical interferometry to spot exoplanet, a first

GRAVITY works by synching the VLT's four unit telescopes to perform like a bigger, more powerful telescope.

By Brooks Hays
The Very Large Telescope's GRAVITY instrumented rendered the spectrum of light passing through an exoplanet's atmosphere in unprecedented detail. Photo by ESO/L. Calçada
The Very Large Telescope's GRAVITY instrumented rendered the spectrum of light passing through an exoplanet's atmosphere in unprecedented detail. Photo by ESO/L. Calçada

March 27 (UPI) -- For the first time, the Very Large Telescope's GRAVITY instrument has observed a distant exoplanet using optical interferometry.

Observations of the exoplanet's atmosphere revealed massive, swirling storm clouds of iron and silicates stretching across the entirety of the alien planet.

Advertisement

Astronomers described GRAVITY's feat and shared details about the observed target, exoplanet HR8799e, in a paper published this week in the journal Astronomy and Astrophysics.

GRAVITY works by synching the VLT's four unit telescopes to perform like a bigger, more powerful telescope. Astronomers at the European Southern Observatory have previously used GRAVITY to precisely render the gas clouds at the center of a quasar lying outside the Milky Way -- also a first.

For the latest feat, scientists chose to target HR8799e, which was first identified in 2010. The exoplanet is a "super-Jupiter" with a thick atmosphere and surface temperatures approaching 1,000 degrees Celsius, or 1,832 degrees Fahrenheit. HR8799e is located 129 light-years away, orbiting a main sequence star in the constellation Pegasus.

By integrating the power of all four to VLT's telescopes, GRAVITY was able to more precisely render the spectrum of light passing through HR8799e's atmosphere. The high-resolution observations allowed scientists to characterize the exoplanet's atmospheric composition.

Advertisement

"Our analysis showed that HR8799e has an atmosphere containing far more carbon monoxide than methane -- something not expected from equilibrium chemistry," Sylvestre Lacour, researcher at the Max Planck Institute for Extraterrestrial Physics, said in a news release. "We can best explain this surprising result with high vertical winds within the atmosphere preventing the carbon monoxide from reacting with hydrogen to form methane."

The GRAVITY data also revealed the presence of clouds of iron and silicate dust, which suggest a planet-wide storm is swirling across the exoplanet's atmosphere.

"Our observations suggest a ball of gas illuminated from the interior, with rays of warm light swirling through stormy patches of dark clouds," Lacour said. "Convection moves around the clouds of silicate and iron particles, which disaggregate and rain down into the interior. This paints a picture of a dynamic atmosphere of a giant exoplanet at birth, undergoing complex physical and chemical processes."

Latest Headlines