HD 183263 b is an extrasolar planet orbiting the star HD 183263

HD 183263

HD 183263 is an 8th magnitude subgiant star located approximately 172 light-years away in the constellation Aquila. This star is about to or already ran out of hydrogen fuel and eventually becomes a red giant and then dies as a white dwarf...

. This planet has a 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...

 of 3.69 times more 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,...

 and takes 1.7364 years to orbit the star. The planet was discovered on January 25, 2005 using multiple Doppler

Doppler spectroscopy

Doppler spectroscopy, also known as radial velocity measurement, is a spectroscopic method for finding extrasolar planets. It involves the observation of Doppler shifts in the spectrum of the star around which the planet orbits....

 measurements of five nearby FGK

Stellar classification

In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

 main-sequence stars and subgiants obtained during the past 4–6 years at the Keck Observatory in Mauna Kea

Mauna Kea

Mauna Kea is a volcano on the island of Hawaii. Standing above sea level, its peak is the highest point in the state of Hawaii. However, much of the mountain is under water; when measured from its oceanic base, Mauna Kea is over tall—significantly taller than Mount Everest...

, Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

. These stars, namely, HD 183263, HD 117207

HD 117207

HD 117207 is a star located approximately 108 light years away in the constellation Centaurus. It is a yellow dwarf or subgiant star of mass 7% greater than our Sun. It has apparent magnitude 7.26 which is not visible to the naked eye and has absolute magnitude of 4.67, which is visible to the...

, HD 188015

HD 188015

HD 188015 is an 8th magnitude star about 172 light-years away in the constellation of Vulpecula. It is a yellow subgiant, a Sun-like star that has ceased or is about to stop hydrogen fusion in its core. However, it is only slightly brighter than the Sun, but probably much older.The star is almost...

, HD 45350

HD 45350

HD 45350 is an 8th magnitude star located approximately 160 light-years away in the constellation of Auriga. It is a yellow subgiant , a Sun-like star that is finishing hydrogen fusion in its core. Although slightly cooler, it is brighter, although not much considering its subgiant status...

, and HD 99492, all exhibit coherent variations in their Doppler shifts consistent with a planet in Keplerian motion

Kepler orbit

In celestial mechanics, a Kepler orbit describes the motion of an orbiting body as an ellipse, parabola, or hyperbola, which forms a two-dimensional orbital plane in three-dimensional space...

, and the results were published in a paper by Geoffrey Marcy

Geoffrey Marcy

Geoffrey W. Marcy is an American astronomer, who is currently Professor of Astronomy at the University of California, Berkeley, famous for discovering more extrasolar planets than anyone else, 70 out of the first 100 to be discovered, along with R...

 et al. Photometric observations were acquired for four of the five host stars with an automatic telescope at Fairborn Observatory. The lack of brightness variations in phase with the radial velocities supports planetary-reflex motion as the cause of the velocity

Velocity

In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant ...

variations.