Kepler-39 (2MASS J19475046+4602034) is an F-type

main sequence In astronomy, 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 Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

star located in the constellation Cygnus. It is located about 3,560 light-years (1,090 parsecs) away. One known

substellar companion A substellar object, sometimes called a substar, is an astronomical object the mass of which is smaller than the smallest mass at which hydrogen fusion can be sustained (approximately 0.08 solar masses). This definition includes brown dwarfs and fo ...

orbits it,

Kepler-39b Kepler-39b (formerly known as KOI-423b), is a confirmed extrasolar object (either a Jovian planet or brown dwarf because of its mass) discovered orbiting the F-type star Kepler-39. It is eighteen times more massive than Jupiter, and is about five ...

Planetary system

Kepler-39b is generally considered a

brown dwarf Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...

rather than a planet since it does not meet the standard

definition of planet The definition of ''planet'', since the word was coined by the ancient Greeks, has included within its scope a wide range of celestial bodies. Greek astronomers employed the term (), 'wandering stars', for star-like objects which apparently m ...

. Some authorities such as the

Extrasolar Planets Encyclopaedia The Extrasolar Planets Encyclopaedia is an astronomy website, founded in Paris, France at the Meudon Observatory by Jean Schneider in February 1995, which maintains a database of all the currently known and candidate extrasolar planets, with indi ...

and the

NASA Exoplanet Archive The NASA Exoplanet Archive is an online astronomical exoplanet catalog and data service that collects and serves public data that support the search for and characterization of extra-solar planets (exoplanets) and their host stars. It is part of ...

include it among their list of confirmed planets.

References

Cygnus (constellation) F-type subgiants Planetary transit variables

423 __NOTOC__ Year 423 (Roman numerals, CDXXIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Marinianus and Asclepiodotus (or, less fr ...

Planetary systems with one confirmed planet J19475046+4602034 {{subgiant-star-stub