Approaching cm/sec calibration of high resolution astronomical spectrograph

Abstract

Radial Velocity measurements have demonstrated to be the most successful way of finding extra solar planets; this technique has reported the larger quantity of exoplanet so far detected. Finding Earth like type exoplanets demands a cm/sec reproducible spectrograph calibration. A Laser Frequency Comb (LFC) calibration system [1], [2] has been developed and tested in several occasions with the HARPS spectrograph [3] at the 3.6m telescope on La Silla ESO Observatory since January 2009. The LFC shows a number of advantages compared to other traditional calibration sources [4].