Search for Jupiter-Mass Companions

Introduction: The experimental technique, in which lines of the 870 nm 3-0 vibration-rotation band of hydrogen fluoride are imposed in absorption on the stellar spectra to act as wavelength fiducials, is capable of measuring long-term changes in the velocity of a star with a precision near 15 m/s from a single spectrum.

For comparison, the orbit of the Sun about the barycentre, which is dominated by the motion of Jupiter, has a period of 11.9 years with an amplitude of some 13 m/s. Thus, by making several observations per year, we could have detected the reflex motion caused by a Jupiter-mass planet orbiting a nearby star provided the orbital plane was close to the line of sight. To date, this planetary search has been the only long-term program on the CFHT.