WASP-189b confirms long-suspected link between planet and star chemistry

Astronomers have for the first time measured magnesium and silicon simultaneously in the atmosphere of exoplanet WASP-189b, 320 light-years away, using the IGRINS spectrograph on the Gemini South telescope. The planet's Mg/Si ratio matches that of its host star, providing the first direct observational support for a long-held assumption about star-planet chemistry.

• WASP-189b is an ultra-hot Jupiter 320 light-years away in Libra
• First simultaneous measurement of magnesium and silicon in an exoplanet atmosphere
• The planet's Mg/Si ratio matches that of its host star
• Observations used the IGRINS spectrograph on Gemini South in Chile