13 relations: Apparent magnitude, Boötes, Bright Star Catalogue, Constellation, Durchmusterung, Giant star, Henry Draper Catalogue, Hipparcos, Irregular variable, Light-year, Smithsonian Astrophysical Observatory Star Catalog, Stellar classification, Variable star.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere.
The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars or Yale Bright Star Catalogue, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the naked eye from Earth.
A constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere, typically representing animals, mythological people or gods, mythological creatures, or manufactured devices.
In astronomy, Durchmusterung or Bonner Durchmusterung (BD), is the comprehensive astrometric star catalogue of the whole sky, compiled by the Bonn Observatory (Germany) from 1859 to 1903.
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature.
The Henry Draper Catalogue (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the Henry Draper Extension Charts (HDEC), published from 1937 to 1949 in the form of charts, which gave classifications for 86,933 more stars.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
An irregular variable is a type of variable star in which variations in brightness show no regular periodicity.
The light-year is a unit of length used to express astronomical distances and measures about 9.5 trillion kilometres or 5.9 trillion miles.
The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates.