11 relations: Apparent magnitude, Ara (constellation), Constellation, Durchmusterung, Epoch (astronomy), Hipparcos, International Celestial Reference System, RR Lyrae variable, Star, Stellar classification, Variable star designation.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Ara (Latin: "The Altar") is a southern constellation situated between Scorpius and Triangulum Australe.
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.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU).
RR Lyrae variables are periodic variable stars, commonly found in globular clusters.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
Variable stars are designated using a variation on the Bayer designation format of an identifying label (as described below) combined with the Latin genitive of the name of the constellation in which the star lies.