F. Wildi, F. Bouchy, R. Doyon, N. Blind, L. Genolet, M. Sordet, A. G. Segovia Milla, N. Grieves, L. Malo, E. Artigau, J. St-Antoine, P. Vallée, J. L. Rasilla, F. Gracia Temich, A.-S. Poulin-Girard, D. Brousseau, D. Sosnowska, V. Reshetov, F. Baron, S. Thibault, S. Bovay, Y. Frensch, G. Lo Curto, N. Hubin, G. Zins, C. Peroux, A. Cabral
NIRPS is an infrared precision Radial Velocity (pRV) spectrograph covering the range 950 nm-1800 nm. NIRPS uses a high-order Adaptive Optics (AO) system to couple the starlight into a fiber corresponding to 0.4" on the sky as efficiently or better than HARPS or ESPRESSO couple the light in a 1.0" fiber. This allows the spectrograph to be very compact, more thermally stable, and less costly. Using a custom tan(θ)=4 dispersion grating in combination with a start-of-the-art Hawaii4RG detector makes NIRPS very efficient with complete coverage of the YJH bands at just under 100 000 resolution. On the ESO 3.6-m telescope, NIRPS and HARPS are working simultaneously on the same target, building a single powerful high-resolution, high-fidelity spectrograph covering the 0.37-1.8 µm domain. NIRPS will complement HARPS in validating Earth-like planets found around G and K-type stars whose signal is at the same order of magnitude than the stellar noise. While the telescope-side AO system was installed on the ESO 3.6-m telescope in 2019, the infrared cryogenic spectrograph has been integrated at the telescope in early-2022 and has had first light in June 2022. Results from the first light mission show that NIRPS performs very nicely, that the AO system works up to magnitude I=14.5, that the transmission matches requirements and that the RV stability of 1 m/s is within reach While performance assessment is ongoing, NIRPS has demonstrated on-sky m/s-level stability over a night and <3 m/s level over two weeks. Limitations on the RV performances arise from modal noise that can be mitigated through better scrambling strategies. Better performances are also expected following a grating upgrade in July 2022; these will be tested in late-2022.
Ground-based and Airborne Instrumentation for Astronomy IX
Christopher J. Evans, Julia J. Bryant, Kentaro Motohara
Proceedings of the SPIE