https://phys.org/news/2018-05-spirou-exoplanet-hunter.html

During the following few nights of this first on-sky exercise, SPIRou gathered an impressive collection of 440 spectra, while demonstrating some of its new capabilities in the process. In particular, SPIRou observed stars much cooler than the Sun known as red dwarfs, a stellar population comprising most of the stars in the neighbourhood of the Solar System, which SPIRou will carefully observe during its major observation program with the aim of finding evidence of nearby planetary systems. SPIRou also observed several hot stars, whose infrared spectra mainly show telluric lines caused by the Earth's atmosphere. Identifying and filtering out such telluric lines from the collected spectra is an essential step in making sense of the light from stars and deciphering the information it contains, in particular about the possible presence of planetary systems.

To detect planetary systems, SPIRou uses a technique known as velocimetry (also called the radial velocity method) that makes use of the Doppler effect to detect the tiny fluctuations in the velocities of stars that provide evidence of the presence of orbiting planets. SPIRou is expected to play a key role in future surveys of nearby planetary systems, in coordination with other ground- and space-based instruments such as ESA's TESS and PLATO satellites, the future James Webb Space Telescope (NASA/ESA), and the European Extremely Large Telescope (ELT).