HD 43691

HD 43691 is a star with an orbiting exoplanet in the constellation Auriga. With an apparent visual magnitude of 8.03, it is too faint to be visible to the naked eye. This system is located at a distance of 279 light years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −29 km/s.

This is a slightly evolved G-type subgiant star with a stellar classification of G0 IV. It is ceasing thermonuclear fusion of hydrogen in its core and will expand to become a red giant. The star has 32% greater mass than the Sun and has a 70% larger girth. It is radiating 2.2 times the luminosity of the Sun from its photosphere at an effective temperature of 5,920 K. The level of chromospheric activity is minimal, allowing for accurate measurement of radial velocity variation.

Planetary system
In July 2007, the star is found to have a super-jovian exoplanet in orbit around it. It has minimum mass two and a half times that of Jupiter and orbits the star closer than Mercury to the Sun.