Abstract
We report the design, installation and testing of a broadband green astro-comb on the HARPS-N spectrograph at the TNG telescope. The astro-comb consists of over 7000 narrow lines (<10-6 nm width) spaced by 16 GHz (0.02 nm at 550 nm) with wavelengths stabilized to the Global Positioning System (GPS) and with flat power from 500 to 620 nm. The narrow lines are used to calibrate the spectrograph and measure its line profile. The short term sensitivity of HARPS-N is measured to be less than 2 cm/s and the long-term drift of the spectrograph is approximately 10 cm/s/day. The astrocomb has been partially automated with future work planned to turn the astro-comb into a fully automated, push button instrument.