51 relations: American Association of Variable Star Observers, Apparent magnitude, Astronomical spectroscopy, Astronomische Gesellschaft Katalog, B-type main-sequence star, Bayer designation, Binary star, Blueshift, Boss General Catalogue, Bright Star Catalogue, Catalogue of rotational velocities of the stars, Constellation, Cygnus (constellation), Durchmusterung, Eta Carinae, Flamsteed designation, General Catalogue of Stellar Radial Velocities, Gravitational energy, Guide Star Catalog, H-alpha, Henry Draper Catalogue, Hipparcos, Hypergiant, Johann Bayer, JP11, Light-year, Luminous blue variable, Mass transfer, Milky Way, Minute and second of arc, Nova, Orbit, Orbital eccentricity, Parsec, PPM Star Catalogue, RAFGL, Red supergiant star, Smithsonian Astrophysical Observatory Star Catalog, SN 2006gy, Solar mass, Spectral line, Star catalogue, Stellar classification, Stellar wind, Supernova, TD1 Catalog of Stellar Ultraviolet Fluxes, Type II supernova, Uranometria, Variable star, Willem Blaeu, ..., 2MASS. Expand index (1 more) » « Shrink index
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.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Astronomical spectroscopy is the study of astronomy using the techniques of spectroscopy to measure the spectrum of electromagnetic radiation, including visible light and radio, which radiates from stars and other celestial objects.
The Astronomische Gesellschaft Katalog (AGK) is an astrometric star catalogue.
A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars are extremely luminous and blue.
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.
A blueshift is any decrease in wavelength, with a corresponding increase in frequency, of an electromagnetic wave; the opposite effect is referred to as redshift.
Boss General Catalogue (GC, sometimes General Catalogue) is an astronomical catalogue containing 33,342 stars.
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.
Catalogue of rotational velocities of the stars is the name for catalogue of projected stellar rotation, publushed in 1982 by Uesugi, A. and Fukuda, I.
Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.
The Christmas season, also called the festive season, or the holiday season (mainly in the U.S. and Canada; often simply called the holidays),, is an annually recurring period recognized in many Western and Western-influenced countries that is generally considered to run from late November to early January.
Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.
Christmas traditions vary from country to country.
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.
Cygnus is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan.
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.
Eta Carinae (η Carinae, abbreviated to η Car), formerly known as Eta Argus, is a stellar system containing at least two stars with a combined luminosity greater than five million times that of the Sun, located around 7,500 light-years (2,300 parsecs) distant in the constellation Carina.
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 General Catalogue of Stellar Radial Velocities is a star catalogue which lists radial velocities for 15,107 stars.
Gravitational energy is the potential energy a body with mass has in relation to another massive object due to gravity.
The Guide Star Catalog (GSC), also known as the Hubble Space Telescope, Guide Catalog (HSTGC), is a star catalog compiled to support the Hubble Space Telescope with targeting off-axis stars.
H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air; it occurs when a hydrogen electron falls from its third to second lowest energy level.
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.
A hypergiant (luminosity class 0 or Ia+) is among the very rare kinds of stars that typically show tremendous luminosities and very high rates of mass loss by stellar winds.
Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer).
JP11 is a star catalog containing about 4000 objects.
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.
Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in both their spectra and brightness.
Mass transfer is the net movement of mass from one location, usually meaning stream, phase, fraction or component, to another.
The Milky Way is the galaxy that contains our Solar System.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.
New Year's Day, also called simply New Year's or New Year, is observed on January 1, the first day of the year on the modern Gregorian calendar as well as the Julian calendar.
In the Gregorian calendar, New Year's Eve (also known as Old Year's Day or Saint Sylvester's Day in many countries), the last day of the year, is on 31 December which is the seventh day of Christmastide.
A nova (plural novae or novas) or classical nova (CN, plural CNe) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star, that slowly fades over several weeks or many months.
In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet.
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.
The PPM Star Catalogue (Positions and Proper Motions Star Catalogue) is the successor of the SAO Catalogue.
RAFGL, the "Revised Air Force Geophysical Laboratory" (S.D. Price and T.L. Murdock, 1983), is a four-color infrared sky survey catalog.
Red supergiants are stars with a supergiant luminosity class (Yerkes class I) of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous.
The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue.
SN 2006gy was an extremely energetic supernova, also referred to as a hypernova or quark-nova, that was discovered on September 18, 2006.
The solar mass is a standard unit of mass in astronomy, equal to approximately.
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies.
A star catalogue (Commonwealth English) or star catalog (American English), is an astronomical catalogue that lists stars.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
A stellar wind is a flow of gas ejected from the upper atmosphere of a star.
A supernova (plural: supernovae or supernovas, abbreviations: SN and SNe) is a transient astronomical event that occurs during the last stellar evolutionary stages of a star's life, either a massive star or a white dwarf, whose destruction is marked by one final, titanic explosion.
In 1978, the TD1 Stellar Ultraviolet Flux Survey cataloged the ultraviolet flux of unreddened stars down to the 10th visual magnitude.
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star.
Uranometria is the short title of a star atlas produced by Johann Bayer.
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates.
Willem Janszoon Blaeu (157121 October 1638), also abbreviated to Willem Jansz.
2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.
2019 (MMXIX) will be a common year starting on Tuesday of the Gregorian calendar, the 2019th year of the Common Era (CE) and Anno Domini (AD) designations, the 19th year of the 3rd millennium, the 19th year of the 21st century, and the 10th and last year of the 2010s decade.
The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in the infrared spectrum and one of the most ambitious such projects.