The High Accuracy Radial Velocity Planet Searcher – 3rd Generations (HARPS3)
HARPS3 is the 3rd generation HARPS instrument, to be installed on an upgraded and roboticized Isaac Newton Telescope (INT) in La Palma in 2021. The main project of HARPS3 is the Terra Hunting Experiment (THE), which will observe 50-100 G- and K- type stars over ten years to search for Earth-like planets in Earth-like orbits. Like previous iterations, HARPS3 features a high resolution (R = 115,000) echelle spectrograph and a wavelength range of 380 – 690 nm. The combination of extreme stability and an extremely well sampled window function will allow us to see Earth-like signatures in RV of 10 cm/sec over ten years of observations.
The Dutch portion of this instrument is on the Cassegrain Adaptor Unit (CAU), to be installed at the Cassegrain focus of the INT, and is a joint project between Leiden University and NOVA. The CAU will provide a stabilized beam feed with an on-sky fiber diameter of 1.4 arcsec to the HARPS3 spectrograph. The major difference between HARPS3 and previous iterations is the polarimetric sub-unit, which has been included in the design from the very start. This polarimetric sub-unit consists of an insertable Quarter Waveplate (QWP) and Half Waveplate (HWP) and a novel Wire-grid Polarimetric Beamsplitter (PBS), which will separate incoming starlight into two parallel beams.
