Abstract

 Report on the progress of building and deploying a new instrument at the McDonald 2.1m telescope: the Exoplanet Transmission Spectroscopic Instrument (ETSI). We have successfully used ETSI at the telescope to observe ~25 exoplanets and detected clear evidence of atmospheres in nearly all, including several never seen before and worthy of follow-up on space and other facilities. We have also used the instrument for other observations that show it flexibility for other science projects.