Free Astronomy Magazine September-October 2018

48 SEPTEMBER-OCTOBER 2018 SPACE CHRONICLES T his colourful image shows the sky around the faint orange dwarf star PDS 70 (in the middle of the image). The bright blue star to the right is χ Centauri. [ESO/Digitized Sky Sur- vey 2. Acknowledgement: Davide De Martin] “Keppler’s results give us a new window onto the complex and poorly-understood early stages of planetary evolution,” comments André Müller, leader of the second team to investigate the young planet. “We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.” By determining the planet’s atmos- pheric and physical properties, the astronomers are able to test theoret- ical models of planet formation. This glimpse of the dust-shrouded birth of a planet was only possible thanks to the impressive technological ca- pabilities of ESO’s SPHERE instru- ment, which studies exoplanets and discs around nearby stars using a technique known as high-contrast imaging — a challenging feat. Even when blocking the light from a star with a coronagraph, SPHERE still has to use cleverly devised ob- serving strategies and data process- ing techniques to filter out the sig- nal of the faint planetary compan- ions around bright young stars at multiple wavelengths and epochs. Thomas Henning, director at the Max Planck Institute for Astronomy and leader of the teams, summarises the scientific adventure: “After more than a decade of enormous ef- forts to build this high-tech ma- chine, now SPHERE enables us to reap the harvest with the discovery of baby planets!” !