高精度視線速度系外惑星探査装置
As with many other extrasolar planets, HD 40307 b was discovered by measuring variations in the radial velocity of the star it orbits. These measurements were made by the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrograph at the Chile-based La Silla Observatory. The discovery was announced at the astrophysics conference that took place in Nantes, France between 16 and 18 June 2008. HD 40307 b was one of three found here at the time.