HD 180902 b is an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

orbiting the K-type star HD 180902 approximately 342 light years away in the constellation Sagittarius.

Discovery

HD 180902 b, along with other planets, was discovered in 2010 by scientists at the

Keck Observatory The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when co ...

. These planets were discovered via

doppler spectroscopy Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in t ...

, which is detecting exoplanets using the star's wobble.

Properties

Orbit HD 180902 b takes 510

days A day is the time period of a full rotation of the Earth with respect to the Sun. On average, this is 24 hours, 1440 minutes, or 86,400 seconds. In everyday life, the word "day" often refers to a solar day, which is the length between two s ...

to orbit its parent star, which is longer than

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

's orbital period, which is 365 days. It orbits at a distance similar to Earth from the sun. HD 180902 orbits with mild

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

Characteristics

HD 180902 b has a minimum mass of 1.685 times the mass of

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

, but since its

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

is not known, the true mass of the planet cannot be detected. According to a theoretical search by the observatory, it may have a radius that is 22.1% larger than Jupiter.

References

External links

* Exoplanets discovered in 2010 Exoplanets detected by radial velocity Sagittarius (constellation) Giant planets {{Sky, 19, 19, 18, -, 23, 33, 29

Discovery

Properties

Characteristics

See also

References

External links