DOPPLER MONITORING OF THE WASP-47 MULTIPLANET SYSTEM

We present precise Doppler observations of WASP-47, a transiting planetary system featuring a hot Jupiter with both inner and outer planetary companions. This system has an unusual architecture and also provides a rare opportunity to measure planet masses in two different ways: the Doppler method, and the analysis of transit-timing variations (TTV). Based on the new Doppler data, obtained with the Planet Finder Spectrograph on the Magellan/ Clay 6.5 m telescope, the mass of the hot Jupiter is 370 + or - 29 M sub([+ in circle]). This is consistent with the previous Doppler determination as well as the TTV determination. For the inner planet WASP-47e, the Doppler data lead to a mass of 12.2 + or - 3.7 M sub([+ in circle]), in agreement with the TTV-based upper limit of