  We present a description of A dual-Beam pOlarimetric Robotic Aperture for the
Sun (ABORAS), to serve as a Solar input with a dedicated Stokes V polarimeter
for the HARPS3 high-resolution spectrograph. ABORAS has three main science
drivers: trying to understand the physics behind stellar variability, tracking
the long-term stability of HARPS3, and serve as a benchmark for Earth-sized
exoplanet detection with HARPS3 by injecting an Earth RV signal into the data.
By design, ABORAS will (together with the HARPS3 instrument) be able to measure
10cm/s variations in RV of the integrated Solar disk and detect integrated
magnetic field levels at sub 1 Gauss level through circularly polarized light.
