An astro-comb is a type of frequency comb used in observational astronomy to increase the accuracy of wavelength calibration in spectrographs. The increased accuracy reduces systematic errors and enhances detection of small variations in stellar radial velocities caused by smaller orbiting exoplanets (e.g. Earth-mass planets), among other applications. Astro-combs are distinguished from conventional frequency combs by their focus on high repetition frequencies (with mode spacings of ≥10 GHz).