Discovery of 'Thermometer' Molecule on Exoplanet WASP-31b

Astronomers have confirmed the presence of chromium hydride (CrH), a temperature-sensitive molecule, in the atmosphere of the hot Jupiter exoplanet WASP-31b. This marks the first detection of a metal hydride from a high-resolution exoplanet spectrum. Chromium hydride is abundant in a specific temperature range of 1,200 to 2,200 Kelvin, making it useful as a "thermometer" to determine the temperature and other characteristics of exoplanets. The discovery provides valuable insights into hot giant planet atmospheres and may encourage further research on metal hydrides in other exoplanets.