ESPRESSO achieves First Light: inside the spectrograph

The Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) successfully made its first observations in November 2017. Installed on ESO’s Very Large Telescope (VLT) in Chile, ESPRESSO will search for exoplanets with unprecedented precision by looking at the minuscule changes in the properties of light coming from their host stars. For the first time ever, an instrument will be able to sum up the light from all four VLT telescopes and achieve the light collecting power of a 16-metre telescope.

This view shows the inside of the vacuum vessel, where the extremely stable spectrographs are located. On the right is the echelle grating and in the centre in blue is the dichroic, which splits red and blue light into separate directions.