Free Astronomy Magazine July-August 2019

JULY-AUGUST 2019 SPACE CHRONICLES S chematic lay-out of the VLT Inter- ferometer. The light from a dis- tant celestial objects enters two of the VLT telescopes and is reflected by the various mirrors into the Interfer- ometric Tunnel, below the observing platform on the top of Paranal. Two Delay Lines with moveable carriages continuously adjust the length of the paths so that the two beams inter- fere constructively and produce fringes at the interferometric focus in the laboratory. [ESO] de Paris - PSL and the Max Planck In- stitute for Extraterrestrial Physics. “We can best explain this surpris- ing result with high vertical winds within the atmosphere pre- venting the carbon monoxide from reacting with hy- drogen to form methane.” The team found that the atmos- phere also con- tains clouds of iron and silicate dust. When com- bined with the excess of carbon monoxide, this suggests that HR-8799e’s atmosphere is en- gaged in an enormous and vi- olent storm. “Our observations suggest a ball of gas illuminated from the interior, with rays of warm light swirling through stormy patches of dark clouds,” elab- orates Lacour. “Convection moves around the clouds of silicate and iron particles, T he above footage consists of 7 images of HR 8799 taken with the Keck Telescope over 7 years. The video was made by Jason Wang, data was reduced by Christian Marois, and the orbits were fit by Quinn Konopacky. Bruce Mac- intosh, Travis Barman, and Ben Zuckerman as- sisted in the observations. [J. Wang et al.] “Our analysis showed that HR8799e has an atmosphere containing far more carbon monoxide than meth- ane — something not expected from equilibrium chemistry,” explains team leader Sylvestre Lacour re- searcher CNRS at the Observatoire which disaggregate and rain down into the interior. This paints a pic- ture of a dynamic atmosphere of a giant exoplanet at birth, undergo- ing complex physical and chemical processes.” This result builds on GRAVITY’s string of impressive discoveries, which have included breakthroughs such as last year’s observation of gas swirling at 30% of the speed of light just outside the event horizon of the massive Black Hole in the Galactic Centre. It also adds a new way of observing exoplanets to the already extensive arsenal of methods available to ESO’s telescopes and instruments — paving the way to many more im- pressive discoveries. T he video on the side summarizes the first direct observation of an exoplanet using optical inter- ferometry. [ESO] !