Doppler spectroscopy
The planet was first discovered by the HARPS spectrometer which is housed at the European Southern Observatory's La Silla Observatory in Chile. Further confirmations of the planetary detection were made at the Keck Observatory in Hawaii and at the PFS Observatory, also in Chile. The method of discovery involved observing and recording tiny wobbles in the star caused by the gravitational tug of its planets, using Doppler spectroscopy.