Editing Astronomical naming conventions (section)

=== Exoplanets ===
{{Main|Exoplanet#Nomenclature}}

Currently, according to the IAU, there is no agreed upon system for designating [[exoplanet]]s (planets orbiting other stars). The process of naming them is organized by the IAU Executive Committee Working Group Public Naming of Planets and Planetary Satellites. The scientific nomenclature for the designations usually consists of a proper noun or abbreviation that often corresponds to the star's name, followed by a lowercase letter (starting with 'b'), like [[51 Pegasi b]].<ref>{{cite web | url = http://www.iau.org/public/themes/naming_exoplanets/ | title = Naming of exoplanets | publisher = International Astronomical Union | access-date = 2014-12-01 }}</ref>

The lowercase lettering style is drawn from the IAU's long-established rules for naming binary and multiple star systems. A primary star, which is brighter and typically bigger than its companion stars, is designated by a capitalized A. Its companions are labelled B, C, and so on. For example, [[Sirius]], the brightest star in the sky, is actually a double star, consisting of the naked-eye visible Sirius A and its dim white-dwarf companion [[Sirius B]]. The first exoplanet tentatively identified around the second brightest star in the triple star system [[Alpha Centauri]] is accordingly called [[Alpha Centauri Bb]]. If an exoplanet orbits both of the stars in a binary system, its name can be, for example, [[Kepler-34(AB) b]].