Free Astronomy Magazine July-August 2019

54 JULY-AUGUST 2019 SPACE CHRONICLES T he GRAVITY instrument on ESO’s Very Large Telescope In- terferometer (VLTI) has made the first direct observation of an ex- oplanet using optical interferome- try. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The tech- nique presents unique possibilities for characterising many of the exo- planets known today. This result was announced today in a letter in the journal Astronomy and Astrophysics by the GRAVITY Collaboration, in which they present observations of the exoplanet HR- 8799e using optical interferometry. The exoplanet was discovered in 2010 orbiting the young main-sequence by ESO star HR8799, which lies around 129 light- years from Earth in the constellation of Pegasus. Today’s result, which re- veals new characteristics of HR8799e, required an instrument with very high resolution and sensitivity. GRAVITY can use ESO’s VLT’s four unit telescopes to work to- gether to mimic a single larger tel- escope using a technique known as interferometry. This creates a super- telescope — the VLTI — that collects GRAVITY breaks new ground in exoplanet imaging T his artist’s impression shows the observed exoplanet, which goes by the name HR8799e. [ESO/L. Calçada]