138 relations: Acoustics, Algol, Amateur astronomy, American Association of Variable Star Observers, Amplitude, Apparent magnitude, Aristotle, Arthur Eddington, Asteroseismology, Astronomical naming conventions, Astronomical spectroscopy, Bayer designation, Beta Canis Majoris, Beta Cephei, Beta Lyrae, Betelgeuse, Binary star, Binary system, BY Draconis variable, Carbon, Carina Nebula, Chandrasekhar limit, Chi Cygni, China, Chromosphere, Constellation, Contact binary, Convection, Crab Nebula, Crab Pulsar, Cygnus (constellation), David Fabricius, Degenerate matter, Delta Cephei, Deneb, Doppler effect, Double star, Dwarf nova, Dwarf star, DY Persei variable, Earth, Eclipse, Edward Pigott, Edwin Hubble, Ellipsoid, Equator, Eta Aquilae, Eta Carinae, Exoplanet, Extreme helium star, ..., FK Comae Berenices, Flare star, Frequency, Friedrich Wilhelm Argelander, Fundamental frequency, Galaxy, Gamma Cassiopeiae, Geminiano Montanari, General Catalogue of Variable Stars, Giant star, Giovanni Domenico Maraldi, Globular cluster, Gottfried Kirch, Gravity, Gravity wave, GSC 02652-01324, Guest star (astronomy), Harmonic, HD 209458, Helioseismology, Helium, Herbig Ae/Be star, Hour, Hydrogen, Hypergiant, Instability strip, Johannes Phocylides Holwarda, John Goodricke, Kepler (spacecraft), Large Magellanic Cloud, Light, Light curve, List of variable stars, Local Group, Low-dimensional chaos in stellar pulsations, Luyten 726-8, Main sequence, Metallicity, Mira, Naked eye, Neutron star, Nitrogen, North America, Nova, Nuclear fusion, Opacity (optics), Overtone, Oxygen, P Cygni, Perseus (constellation), Photometry (astronomy), Pre-main-sequence star, Pressure, Proxima Centauri, Pulsar, R Andromedae, R Coronae Borealis, R Hydrae, Red giant, Red supergiant star, Resonance, Rho Cassiopeiae, RR Lyrae, S Doradus, SN 1987A, Solar cycle, Solar-like oscillations, Spectral line, Spectrophotometry, Spectroscopy, Star, Stellar classification, Stellar population, Stellar pulsation, Stochastic, Subdwarf B star, Sun, Sunspot, Supergiant star, Supernova, Supernova impostor, Supernova remnant, T Tauri star, Telescope, V1500 Cygni, Wave interference, White dwarf, Wolf 359. Expand index (88 more) » « Shrink index
Acoustics is the branch of physics that deals with the study of all mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound.
Algol, designated Beta Persei (β Persei, abbreviated Beta Per, β Per), known colloquially as the Demon Star, is a bright multiple star in the constellation of Perseus and one of the first non-nova variable stars to be discovered.
Amateur astronomy is a hobby whose participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes.
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 amplitude of a periodic variable is a measure of its change over a single period (such as time or spatial period).
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Aristotle (Ἀριστοτέλης Aristotélēs,; 384–322 BC) was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidiki, in the north of Classical Greece.
Sir Arthur Stanley Eddington (28 December 1882 – 22 November 1944) was an English astronomer, physicist, and mathematician of the early 20th century who did his greatest work in astrophysics.
Asteroseismology or astroseismology is the study of oscillations in stars.
In ancient times, only the Sun and Moon, a few hundred stars and the most easily visible planets had names.
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.
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.
Beta Canis Majoris (β Canis Majoris, abbreviated Beta CMa, β CMa), also named Mirzam, is a star in the southern constellation of Canis Major, the "Great Dog", located at a distance of about 500 light-years (150 parsecs) from the Sun.
Beta Cephei (β Cephei, abbreviated Beta Cep, β Cep), also named Alfirk, is a third magnitude star in the constellation of Cepheus.
Beta Lyrae (Latinized from β Lyrae, abbreviated Beta Lyr, β Lyr), also named Sheliak, is a binary star system approximately from the Sun in the constellation of Lyra.
Betelgeuse, also designated Alpha Orionis (α Orionis, abbreviated Alpha Ori, α Ori), is the ninth-brightest star in the night sky and second-brightest in the constellation of Orion.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter (also see animated examples).
BY Draconis variables are variable stars of late spectral types, usually K or M, and typically belong to the main sequence.
Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.
The Carina Nebula (catalogued as NGC 3372; also known as the Grand Nebula, Great Nebula in Carina, or Eta Carinae Nebula) is a large, complex area of bright and dark nebulosity in the constellation Carina, and is located in the Carina–Sagittarius Arm.
The Chandrasekhar limit is the maximum mass of a stable white dwarf star.
Chi Cygni (χ Cyg, χ Cygni) is a variable star of the Mira type in the constellation Cygnus, and also an S-type star.
China, officially the People's Republic of China (PRC), is a unitary one-party sovereign state in East Asia and the world's most populous country, with a population of around /1e9 round 3 billion.
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.
The chromosphere (literally, "sphere of color") is the second of the three main layers in the Sun's atmosphere and is roughly 3,000 to 5,000 kilometers deep.
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, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes.
Convection is the heat transfer due to bulk movement of molecules within fluids such as gases and liquids, including molten rock (rheid).
The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant in the constellation of Taurus.
The Crab Pulsar (PSR B0531+21) is a relatively young neutron star.
Cygnus is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan.
David Fabricius (9 March 1564 – 7 May 1617) was a German pastor who made two major discoveries in the early days of telescopic astronomy, jointly with his eldest son, Johannes Fabricius (1587–1615).
Degenerate matter is a highly dense state of matter in which particles must occupy high states of kinetic energy in order to satisfy the Pauli exclusion principle.
Delta Cephei (δ Cep, δ Cephei) is the Bayer designation for a quadruple star system located approximately 887 light-years away in the northern circumpolar constellation of Cepheus, the King.
Deneb, also designated α Cygni (Latinised alpha Cygni, abbreviated Alpha Cyg, α Cyg), is the brightest star in the constellation of Cygnus.
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 observational astronomy, a double star or visual double is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope.
A U Geminorum-type variable star, or dwarf nova (pl. novae) is a type of cataclysmic variable star consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion.
A dwarf star is a star of relatively small size and low luminosity.
DY Persei variables are a subclass of R Coronae Borealis (R CrB) variables.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer.
Edward Pigott (1753–1825) was an English astronomer.
Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer.
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
An equator of a rotating spheroid (such as a planet) is its zeroth circle of latitude (parallel).
Eta Aquilae (η Aql, η Aquilae) is the Bayer designation for a multiple star in the equatorial constellation of Aquila, the eagle.
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.
An exoplanet or extrasolar planet is a planet outside our solar system.
An extreme helium star (abbreviated EHe) is a low-mass supergiant that is almost devoid of hydrogen, the most common chemical element of the Universe.
FK Comae Berenices is a variable star that varies in apparent magnitude between 8.14m and 8.33m over a period of 2.4 days.
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes.
Frequency is the number of occurrences of a repeating event per unit of time.
Friedrich Wilhelm August Argelander (22 March 1799 – 17 February 1875) was a German astronomer.
The fundamental frequency, often referred to simply as the fundamental, is defined as the lowest frequency of a periodic waveform.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.
Gamma Cassiopeiae, Latinized from γ Cassiopeiae, is a star at the center of the distinctive "W" asterism in the northern circumpolar constellation of Cassiopeia.
Geminiano Montanari. Geminiano Montanari (June 1, 1633 – October 13, 1687) was an Italian astronomer, lens-maker, and proponent of the experimental approach to science.
The General Catalogue of Variable Stars (GCVS) is a list of variable stars.
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature.
Giovanni Domenico Maraldi (17 April 1709 – 14 November 1788) was an Italian-born astronomer, nephew of Giacomo F. Maraldi.
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.
Gottfried Kirch (Kirche, Kirkius) (December 18, 1639 – July 25, 1710) was a German astronomer and the first 'Astronomer Royal' in Berlin and, as such, director of the nascent Berlin Observatory.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media when the force of gravity or buoyancy tries to restore equilibrium.
GSC 02652-01324 is an orange dwarf main sequence star approximately 520 light-years away in the constellation of Lyra (the Lyre).
In Chinese astronomy, a guest star is a star which has suddenly appeared in a place where no star had previously been observed and becomes invisible again after some time.
A harmonic is any member of the harmonic series, a divergent infinite series.
HD 209458 is an 8th-magnitude star in the constellation Pegasus.
Helioseismology, a term coined by Douglas Gough, is the study of the structure and dynamics of the Sun through its oscillations.
Helium (from lit) is a chemical element with symbol He and atomic number 2.
A Herbig Ae/Be star (HAeBe) is a pre-main-sequence star – a young (V. Mannings & A. Sargent (2000) High-resolution studies of gas and dust around young intermediate-mass stars: II. observations of an additional sample of Herbig Ae/Be systems. Astrophysical Journal, vol. 529, p. 391 Hydrogen and calcium emission lines are observed in their spectra. They are 2-8 Solar mass objects, still existing in the star formation (gravitational contraction) stage and approaching the main sequence (i.e. they are not burning hydrogen in their center). In the Hertzsprung–Russell diagram these stars are located to the right of the main sequence. They are named after the American astronomer George Herbig, who first distinguished them from other stars in 1960. The original Herbig criteria were.
An hour (symbol: h; also abbreviated hr.) is a unit of time conventionally reckoned as of a day and scientifically reckoned as 3,599–3,601 seconds, depending on conditions.
Hydrogen is a chemical element with symbol H and atomic number 1.
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.
The unqualified term instability strip usually refers to a region of the Hertzsprung–Russell diagram largely occupied by several related classes of pulsating variable stars: Delta Scuti variables, SX Phoenicis variables, and rapidly oscillating Ap stars (roAps) near the main sequence; RR Lyrae variables where it intersects the horizontal branch; and the Cepheid variables where it crosses the supergiants.
Johannes Phocylides Holwarda (Jan Fokkesz, Jan Fokker, Johann Holwarda, Johannes Fokkes Holwarda, Jan Fokkens Holwarda, Jan Fokkes van haylen) (February 19, 1618—January 22, 1651) was a Frisian astronomer, physician, and philosopher.
John Goodricke FRS (17 September 1764 – 20 April 1786) was an English amateur astronomer.
Kepler is a space observatory launched by NASA to discover Earth-size planets orbiting other stars.
The Large Magellanic Cloud (LMC) is a satellite galaxy of the Milky Way.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
In astronomy, a light curve is a graph of light intensity of a celestial object or region, as a function of time.
There are over 41,638 known variable stars (2008), with more being discovered regularly, so a complete list of every single variable is impossible at this place (cf. GCVS).
The Local Group is the galaxy group that includes the Milky Way.
Low-dimensional chaos in stellar pulsations is the current interpretation of an established phenomenon.
Luyten 726-8, also known as Gliese 65, is a binary star system that is one of Earth's nearest neighbors, at about 8.7 light years from Earth in the constellation Cetus.
In astronomy, the main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness.
In astronomy, metallicity is used to describe the abundance of elements present in an object that are heavier than hydrogen or helium.
Mira, alternatively designated Omicron Ceti (ο Ceti, abbreviated Omicron Cet, ο Cet) is a red giant star estimated to be 200–400 light years from the Sun in the constellation of Cetus.
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying or light-collecting optical instrument, such as a telescope or microscope.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
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.
Nitrogen is a chemical element with symbol N and atomic number 7.
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas.
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 nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light.
An overtone is any frequency greater than the fundamental frequency of a sound.
Oxygen is a chemical element with symbol O and atomic number 8.
P Cygni (34 Cyg) is a variable star in the constellation Cygnus.
Perseus is a constellation in the northern sky, being named after the Greek mythological hero Perseus.
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation.
A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence.
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
Proxima Centauri, or Alpha Centauri C, is a red dwarf, a small low-mass star, about from the Sun in the constellation of Centaurus.
A pulsar (from pulse and -ar as in quasar) is a highly magnetized rotating neutron star or white dwarf that emits a beam of electromagnetic radiation.
R Andromedae (R And) is a Mira-type variable star in the constellation Andromeda.
R Coronae Borealis is a peculiar low-mass yellow supergiant star in the constellation of Corona Borealis.
R Hydrae, also known as R Hya, is a Mira-type variable star in the constellation Hydra.
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses) in a late phase of stellar evolution.
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.
In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies.
Rho Cassiopeiae (ρ Cas, ρ Cassiopeiae) is a yellow hypergiant star in the constellation Cassiopeia.
RR Lyrae is a variable star in the Lyra constellation, located near the border with the neighboring constellation of Cygnus.
S Doradus (also known as S Dor) is located 160,000 light years away, and is one of the brightest stars in the Large Magellanic Cloud (LMC), a satellite of the Milky Way.
SN 1987A was a peculiar type II supernova in the Large Magellanic Cloud, a dwarf galaxy satellite of the Milky Way.
The solar cycle or solar magnetic activity cycle is the nearly periodic 11-year change in the Sun's activity (including changes in the levels of solar radiation and ejection of solar material) and appearance (changes in the number and size of sunspots, flares, and other manifestations).
Solar-like oscillations are oscillations in distant stars that are excited in the same way as those in the Sun, namely by turbulent convection in its outer layers.
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.
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
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.
During 1944, Walter Baade categorized groups of stars within the Milky Way into bluer stars associated with the spiral arms and the general position of yellow stars near the central galactic bulge or within globular star clusters.
Stellar pulsations are caused by expansions and contractions in the outer layers as a star seeks to maintain equilibrium.
The word stochastic is an adjective in English that describes something that was randomly determined.
A B-type subdwarf (sdB) is a kind of subdwarf star with spectral type B. They differ from the typical subdwarf by being much hotter and brighter.
The Sun is the star at the center of the Solar System.
Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas.
Supergiants are among the most massive and most luminous stars.
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.
Supernova impostors are stellar explosions that appear at first to be a type of supernova but do not destroy their progenitor stars.
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova.
T Tauri stars (TTS) are a class of variable stars associated with youth.
A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).
V1500 Cygni or Nova Cygni 1975 was a bright nova occurring in 1975 in the constellation Cygnus.
In physics, interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.
A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.
Wolf 359 is a red dwarf star located in the constellation Leo, near the ecliptic.
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.
Eclipsing Variable star, Eruptive variable, Extrinsic variable, FK Comae Berenices variable, FK Comae star, Intrinsic variable, Long secondary period variable, Planetary transit variable, Pulsating star, Pulsating variable, Pulsating variable star, R corona borealis star, Rotating variable, Stellar variation, Variable stars, Variable-star, Z Andromedae variable.