for NASA's cancelled Terrestrial Planet Finder mission. Red dwarf The red dwarf companion has a spectral type M4.5V and is located at a projected separation of 750 AU from the primary star. The true separation between the two stars is unknown because the displacement along the line of sight between Earth and the Upsilon Andromedae stars is unknown, so this value is a minimum separation. Based upon its motion through space, this is a common proper motion companion to the primary. It was discovered in 2002 in data collected as part of the Two-Micron All Sky Survey. The star is less massive and far less luminous than the Sun, and its age seems to be consistent with that of the system. Planetary system The star rotates at an inclination of degrees relative to Earth. The innermost planet of the Upsilon Andromedae system was discovered in 1996 and announced in January 1997, together with the planet of Tau Boötis and the innermost planet of 55 Cancri. The discovery was made by Geoffrey Marcy and R. Paul Butler, both astronomers at San Francisco State University. The planet, designated Upsilon Andromedae b, was discovered by measuring changes in the star's radial velocity induced by the planet's gravity. Because of its closeness to the parent star, it induced a large wobble which was detected relatively easily. The planet appears to be responsible for enhanced activity in the chromosphere of its star. Even when the first planet was taken into account, there still remained significant residuals in the radial velocity measurements, and it was suggested there might be a second planet in orbit. In 1999, astronomers at both San Francisco State University and the Harvard-Smithsonian Center for Astrophysics independently concluded that a three-planet model best fit the data. The two outer planets were designated Upsilon Andromedae c and Upsilon Andromedae d in order of increasing distance from the star. Both of these planets are in more eccentric orbits than any of the planets in the Solar System (including Pluto). Upsilon Andromedae d resides in the system's habitable zone. The orbital parameters of this three-planet system have been fully determined. The system is not coplanar, with each other or with the stellar rotation, as in our Solar System. Simulations shows that the measured configuration of the planets produces indeed stable orbits for at least 100 million years, where planets b and d remain roughly coplanar. General