A dispersed fourier transform spectrometer with intrinsic optical metrology for stellar radial velocity measurements

Abstract

Radial velocity (RV) of stellar targets were measured using a dispersed Fourier transform spectrometer (dFTS). The instrument used a laser based optical metrology system in cooperation with a mechanical metrology system to measure the absolute position of the retro-reflectors in the dFTS with a precision of 0.1 nm. The combined metrology system data allowed stellar RV measurements to be precise at the 10 m/s level, or about 0.1% relative error with respect to the RV amplitude. The dFTS instrument is well suited for precise RV measurements, and is less cumbersome to calibrate and operate than echelle spectrometers - a competing instrument for RV measurements of stellar targets.