NIRPS: the Near-InfraRed Planet Searcher joining HARPS on the 3.6-m

The Near-InfraRed Planet Searcher (NIRPS) is designed to be an ultra-stable infrared spectrograph to be installed on ESO’s 3.6 m Telescope in La Silla, Chile. NIRPS is an adaptive optics (AO) fiber-fed spectrograph operating from 0.98 to 1.8 μm and will be operated simultaneously with the optical high-resolution spectrograph HARPS. NIRPS can operate in two modes fed by two different fiber links permanently mounted at the Cassegrain focus that use either 0.4 arcsecond-fibers for the High Accuracy Mode (HAM) or 0.9 arcsecond-fibers for the High Efficiency Mode (HEM). The wavelength range of NIRPS is optimal for low-mass M dwarfs and the simultaneous NIRPS and HARPS observations will improve stellar activity filtering methods given their different wavelength coverages. The NIRPS front-end and AO system were already tested on-sky at La Silla. The spectrograph and back-end is being shipped to La Silla and installed in Summer/Fall 2021. Already we have adapted the state-of-the-art ESPRESSO data reduction pipeline for NIRPS, obtained accurate wavelength solutions with a Uranium Neon lamp, and obtained drift stability results below 50 cm/s with a Fabry–Pérot etalon. We discuss the current and expected instrument performance and the expected results of NIRPS.