HD 38529

 
HD 38529 (138 G. Orionis) is a binary star approximately 138 light-years away in the constellation of Orion.
HD 38529 A.
HD 38529 A is a yellow subgiant star, which has also been classified as a main sequence dwarf of spectral type G4V. It is about 40% more massive than our Sun. Two substellar companions are known in orbit around this star, including one with a mass above the deuterium fusion limit that is often used as the dividing line between giant planets and brown dwarfs. There is a debris disk located at least 86 astronomical units from the star. Its orbit is probably mildly misaligned with planetary orbits, by 21−45°.
Planetary system.
In 2002, the planet HD 38529 b was discovered orbiting the star HD 38529 A by Debra Fischer and collaborators who detected it using the doppler spectroscopy technique. It has mass 78% that of Jupiter and orbits very close to the star, just beyond the distance limit for hot Jupiters. One year later, a massive superjovian HD 38529 c was found orbiting at 3.68 AU with a minimum mass of 12.7 Jupiter masses. Astrometric measurements from the Hipparcos satellite gave a best fit inclination of 160° and a true mass 37 times that of Jupiter, turning this planet into a brown dwarf. Further study of the system using Hubble Space Telescope astrometry revised the mass of HD 38529 c downwards to 17.7 Jupiter masses and suggested the presence of an additional planet, orbiting in the gap between HD 38529 b and c. The possible third planet was refuted after additional radial velocity measurements were collected.
HD 38529 B.
HD 38529 B is a common proper motion stellar companion to HD 38529 A at a projected distance of about ~12000 Astronomical units. The star is a red dwarf of spectral type M3.0V. Wide binary stars such as HD 38529 AB have been shown to be vulnerable to disruption by galactic tides and perturbations by passing stars.