26 relations: A-type main-sequence star, American Association of Variable Star Observers, Angular resolution, Apparent magnitude, Bayer designation, Binary star, Blue giant, Bright Star Catalogue, Constellation, Doppler effect, Durchmusterung, Epoch (astronomy), Flamsteed designation, Henry Draper Catalogue, Hipparcos, International Celestial Reference System, Light-year, Orbital eccentricity, Parsec, Serpens, Slowly pulsating B-type star, Smithsonian Astrophysical Observatory Star Catalog, Spectrum, Star system, Stellar parallax, Variable star designation.
An A-type main-sequence star (A V) or A dwarf star is a main-sequence (hydrogen-burning) star of spectral type A and luminosity class V. These stars have spectra which are defined by strong hydrogen Balmer absorption lines.
Since its founding in 1911, the American Association of Variable Star Observers (AAVSO) has coordinated, collected, evaluated, analyzed, published, and archived variable star observations made largely by amateur astronomers and makes the records available to professional astronomers, researchers, and educators.
Angular resolution or spatial resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II (bright giant).
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.
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.
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.
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the modern constellations visible from southern England.
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.
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU).
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 orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.
The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.
Serpens ("the Serpent", Greek Ὄφις) is a constellation of the northern hemisphere.
A slowly pulsating B-type star (SPB), formerly known as a 53 Persei variable, is a type of pulsating variable star.
The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction.
Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects.
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.