HD 147018 b
Encyclopedia
HD 147018 b is a gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...

 extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...

 which orbits the G-type main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprungā€“Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...

 star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 HD 147018
HD 147018
HD 147018 is a G-type main sequence star in the constellation of Triangulum Australe. It has an apparent visual magnitude of approximately 8.4. In August 2009, two extrasolar planets, HD 147018 b and HD 147018 c, were reported to be orbiting this star...

, located approximately 140 light years away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Triangulum Australe
Triangulum Australe
Triangulum Australe is a small constellation in the southern sky, created in the sixteenth century. Its name is Latin for 'the southern triangle', which distinguishes it from Triangulum in the northern sky...

. This planet has minimum mass
Minimum mass
In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars and binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets...

 more than twice that of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

 but this planet orbits lot closer to the star than Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

 to the Sun by a factor of 22. Meanwhile, it has an eccentric orbit. The planet can get as close to the star as 0.13 AU or can get as far as 0.35 AU. Further out, there is another superjovian planet HD 147018 c
HD 147018 c
HD 147018 c is a gas giant extrasolar planet which orbits the G-type main sequence star HD 147018, located approximately 140 light years away in the constellation Triangulum Australe. It has mass at least six and a half time more than Jupiter and orbits the twice nearly twice the distance between...

, which was discovered on the same date as this planet, on August 11, 2009.
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