|
55 Cancri is a G type star 41 light-years or 12.57 parsecs away in the constellation Cancer.
Four extrasolar planets have been discovered around 55 Cancri, making it the largest known extrasolar planetary system as of August 2004. Its planets orbit with periods of 3, 15, 44 and 4,520 days. The smallest planet, which orbits the star in just under three days, is about the same size as Neptune, making it one of the smallest extrasolar planets ever discovered. This is the first and only known four planet planetary system.
55 Cancri is visible through binoculars.
The planets
- 55 Cancri e, discovered in 2004, is a large gas giant orbiting close to the star; it takes only 3 days to complete an orbit. It is about the mass of Neptune, but is believed to be smaller and rockier in composition. As it is very close to 55 Cancri, its surface would be highly volcanic. [1] (http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=268)
- 55 Cancri b was discovered in 1996. A gas giant, its size is similar to that of Jupiter, but it is much closer to its sun, with an orbital period of only 14 days. Given its chemistry and position, it is likely to be a featureless, hazy blue planet. [2] (http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=9)
- 55 Cancri c, discovered in 2002 and confirmed in 2004, is about a quarter the mass of Jupiter. It is a gas giant with an unusually eccentric orbit; sometimes it is almost as close to 55 Cancri as planet b, other times it is twice as distant. This would produce extreme seasons on its surface. [3] (http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=10)
- 55 Cancri d, discovered in 2002 is a gas giant four times as massive as Jupiter that orbits at a distance from the star similar to that of Jupiter. Its composition and distance suggest that is probably pale in colouring. [4] (http://www.extrasolar.net/planettour.asp?StarCatId=&PlanetId=192)
See also
External links and references
|
