HD 69830 d

HD 69830 d is an extrasolar planet orbiting the K-type main-sequence star HD 69830 every 197 days. It is the outermost known planet in its planetary system and possibly lies within its habitable zone.

Discovery
Planet HD 69830 d was discovered in 2006.

Orbit and mass
The planet's orbit has a low eccentricity, like most of the planets in our solar system. The semimajor axis of the orbit is only 0.63 AU, similar to that of Venus. However, HD 69830 is a less massive and energetic star than the Sun, thereby putting the planet within its habitable zone. It is 17 times the mass of the Earth, and 42 light years away from the solar system, and has a close to circular orbit.

Characteristics
Given the planet's Neptune-type mass, it is likely that HD 69830 d is a gas giant with no solid surface. Since the planet has only been detected indirectly through its gravitational effects on the star, properties such as its radius and composition are unknown.