Logo
Unionpedia
Communication
Get it on Google Play
New! Download Unionpedia on your Android™ device!
Free
Faster access than browser!
 

A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity. [1]

399 relations: Abd al-Rahman al-Sufi, Absolute magnitude, Achernar, Age of the universe, Al-Andalus, Al-Biruni, Albert A. Michelson, Algol, Ali ibn Ridwan, Alpha particle, Altair, Ancient Greece, Ancient Greek astronomy, Ancient Greek philosophy, Ancient Greek religion, Andromeda Galaxy, Angelo Secchi, Angular diameter, Angular momentum, Annie Jump Cannon, Apparent magnitude, Arabic, Aristyllus, Asterism (astronomy), Astrology, Astronomer, Astronomical constant, Astronomical object, Astronomical spectroscopy, Astronomical unit, Astronomy, Astronomy in the medieval Islamic world, Asymptotic giant branch, Atacama Large Millimeter Array, Atomic nucleus, Avempace, Babylon, Babylonian astronomy, Babylonian star catalogues, Bad Astronomy, Bayer designation, Beryllium, Beta particle, Betelgeuse, Big Bang, Binary star, Binding energy, Black dwarf, Black hole, Blue dwarf (red-dwarf stage), ..., Blue straggler, Blue supergiant star, Bok globule, Book of Fixed Stars, Brightness, British Library, Brocchi's Cluster, Brown dwarf, Business, Cambridge University Press, Canopus, Carbon, Carbon-12, Carbon-burning process, Cataclysmic variable star, Catalysis, Cecilia Payne-Gaposchkin, Celestial navigation, Celestial spheres, Centimetre–gram–second system of units, Centre de données astronomiques de Strasbourg, Cepheid variable, Chemical element, Chemically peculiar star, Chinese astronomy, Chromium, Chromosphere, Civilization, CNO cycle, Color index, Common envelope, Compact star, Concentration, Conjunction (astronomy), Constellation, Contact binary, Convection, Convection zone, Corona, Coronal loop, Cosmic dust, Cosmology in medieval Islam, Cosmos Redshift 7, Crab Nebula, Degenerate matter, Democritus, Density, Deuterium, Doppler effect, Dynamo theory, Earth, Ecliptic, Edmond Halley, Edward Charles Pickering, Effective temperature, Egyptian astronomy, Electromagnetic radiation, Electromagnetic spectrum, Electron capture, Electronvolt, Energy flux, Epicurus, Epsilon Indi, Eta Carinae, Exoplanet, Extinction (astronomy), Fairfield University, Fakhr al-Din al-Razi, First magnitude star, Flamsteed designation, Flare star, Frequency, Friedrich Bessel, Friedrich Georg Wilhelm von Struve, Fuel, G-type main-sequence star, Galactic Center, Galactic Disc, Galaxy, Gamma ray, Gas giant, Geminiano Montanari, Giant star, Giordano Bruno, Globular cluster, Gradient, Gravitational collapse, Gravitational constant, Gravitational microlensing, Gravity, Greek mythology, Gregorian calendar, H II region, Hayashi track, HD 140283, Heat transfer, Heliosphere, Helium, Helium flash, Helium-3, Helium-4, Henyey track, Herbig Ae/Be star, Herbig–Haro object, Hertzsprung–Russell diagram, Hipparchus, Horizontal branch, Human eye, Hydrogen, Hydrogen line, Hydrostatic equilibrium, Hypergiant, IAU Working Group on Star Names, Infrared, Interacting galaxy, Interferometry, International Astronomical Union, International Star Registry, International System of Units, Interstellar medium, Inverse beta decay, Ion, Iron, Isaac Newton, Isis (journal), Islamic calendar, Isotopes of beryllium, Isotopes of hydrogen, Jeans instability, Johann Bayer, John Flamsteed, John Herschel, Joseph von Fraunhofer, Jupiter, Karl Schwarzschild, Kassites, Kelvin, Large Magellanic Cloud, Latin, Latitude, LBV 1806-20, Life, Light-year, Limb darkening, List of Arabic star names, List of largest stars, Lists of stars, Lithium, Local Group, Logarithmic scale, Luminosity, Lunar eclipse, Luyten 726-8, MACS J1149 Lensed Star 1, Magnetic field, Main sequence, Mars, Mass, Mass–energy equivalence, Maunder Minimum, Mercury (planet), Mesopotamia, Metallicity, Milky Way, Minute and second of arc, Mira variable, Molecular cloud, Monthly Notices of the Royal Astronomical Society, Moon, Mount Wilson Observatory, Mu Leonis, Mythology, Names of large numbers, Nature (journal), Nebula, Neon, Neon-burning process, Neptune, Neutrino, Neutron star, New York City Department of Consumer Affairs, NGC 6397, Night sky, Nova, Nth root, Nuclear fission, Nuclear fusion, O-type star, Observable universe, Observatory, Occultation, Omicron Velorum, Opacity (optics), Open cluster, Orbit, Orbital elements, Orion (constellation), Orion Nebula, Outer space, Outline of astronomy, Oxygen, Oxygen-burning process, Parallax, Particle radiation, Persian people, Photoelectric effect, Photograph, Photographic magnitude, Photometer, Photon, Photosphere, Planck (spacecraft), Planet, Planetary nebula, Planetary system, Plasma (physics), Polymath, Positron, Power (physics), Pre-main-sequence star, Pressure gradient, Procyon, Proper motion, Proton, Proton–proton chain reaction, Protoplanetary disk, Protostar, Proxima Centauri, Ptolemy, Pulsar, QCD matter, Quantum mechanics, R Doradus, R136, Radial velocity, Radiant energy, Radiation, Radiation pressure, Radiation zone, Radio frequency, Radius, Rare-earth element, Red clump, Red dwarf, Red giant, Red supergiant star, Red-giant branch, Redshift, Refraction, Regulation, Reionization, Richard Bentley, Rigel, Right ascension, Roche lobe, Roman mythology, Rotation, Saturn, Second, Semi-major and semi-minor axes, Sherburne Wesley Burnham, Shock wave, Sidereal time, Silicon, Silicon-burning process, Sirius, SN 1006, SN 1054, SN 185, Solar calendar, Solar eclipse, Solar flare, Solar luminosity, Solar mass, Solar radius, Solar wind, Space Shuttle, Space.com, Spectral line, Spectroscopy, Spheroid, Spicule (solar physics), Spiral galaxy, Stanford Encyclopedia of Philosophy, Star catalogue, Star chart, Star clock, Star cluster, Star count, Star formation, Star system, Starburst galaxy, Stars and planetary systems in fiction, Starspot, Stellar association, Stellar atmosphere, Stellar classification, Stellar designations and names, Stellar dynamics, Stellar evolution, Stellar kinematics, Stellar mass, Stellar nucleosynthesis, Stellar population, Stellar wind, Students for the Exploration and Development of Space, Sun, Sunspot, Supergiant star, Supernova, Supernova nucleosynthesis, Supernova remnant, Surface gravity, T Tauri star, Telescope, The Astrophysical Journal, The New York Times, Thermal equilibrium, Thermonuclear fusion, Timocharis, Triple-alpha process, Twinkle, Twinkle, Little Star, Twinkling, Tycho Brahe, Type Ia supernova, Ultraviolet, Unfair business practices, Universe, University of California, Uranus, Vacuum chamber, Vega, Venus, Very Large Telescope, Virgo Cluster, Virgo Supercluster, Wavelength, White dwarf, William Herschel, Wolf–Rayet star, X-ray, X-ray burster, Yale University Press, Zeta Ophiuchi, Zeta Ursae Majoris, Zij, 14 Herculis, 2MASS J0523-1403, 61 Cygni. Expand index (349 more) »

Abd al-Rahman al-Sufi

'Abd al-Rahman al-Sufi (عبدالرحمن صوفی (December 7, 903 in Rey, Iran – May 25, 986 in Shiraz, Iran) was a Persian astronomer also known as 'Abd ar-Rahman as-Sufi, 'Abd al-Rahman Abu al-Husayn, 'Abdul Rahman Sufi, or 'Abdurrahman Sufi and, historically, in the West as Azophi and Azophi Arabus. The lunar crater Azophi and the minor planet 12621 Alsufi are named after him. Al-Sufi published his famous Book of Fixed Stars in 964, describing much of his work, both in textual descriptions and pictures. Al-Biruni reports that his work on the ecliptic was carried out in Shiraz. He lived at the Buyid court in Isfahan.

New!!: Star and Abd al-Rahman al-Sufi · See more »

Absolute magnitude

Absolute magnitude is a measure of the luminosity of a celestial object, on a logarithmic astronomical magnitude scale.

New!!: Star and Absolute magnitude · See more »

Achernar

Achernar is the name of the primary (or 'A') component of the binary system designated Alpha Eridani (α Eridani, abbreviated Alf Eri, α Eri), which is the brightest 'star' or point of light in, and lying at the southern tip of, the constellation of Eridanus, and the tenth-brightest in the night sky.

New!!: Star and Achernar · See more »

Age of the universe

In physical cosmology, the age of the universe is the time elapsed since the Big Bang.

New!!: Star and Age of the universe · See more »

Al-Andalus

Al-Andalus (الأنْدَلُس, trans.; al-Ándalus; al-Ândalus; al-Àndalus; Berber: Andalus), also known as Muslim Spain, Muslim Iberia, or Islamic Iberia, was a medieval Muslim territory and cultural domain occupying at its peak most of what are today Spain and Portugal.

New!!: Star and Al-Andalus · See more »

Al-Biruni

Abū Rayḥān Muḥammad ibn Aḥmad Al-Bīrūnī (Chorasmian/ابوریحان بیرونی Abū Rayḥān Bērōnī; New Persian: Abū Rayḥān Bīrūnī) (973–1050), known as Al-Biruni (البيروني) in English, was an IranianD.J. Boilot, "Al-Biruni (Beruni), Abu'l Rayhan Muhammad b. Ahmad", in Encyclopaedia of Islam (Leiden), New Ed., vol.1:1236–1238.

New!!: Star and Al-Biruni · See more »

Albert A. Michelson

Albert Abraham Michelson FFRS HFRSE (December 19, 1852 – May 9, 1931) was an American physicist known for his work on measuring the speed of light and especially for the Michelson–Morley experiment.

New!!: Star and Albert A. Michelson · See more »

Algol

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.

New!!: Star and Algol · See more »

Ali ibn Ridwan

Abu'l Hassan Ali ibn Ridwan Al-Misri, أبو الحسن علي بن رضوان المصري (c. 988 - c. 1061) was an Arab of Egyptian origin who was a physician, astrologer and astronomer, born in Giza. He was a commentator on ancient Greek medicine, and in particular on Galen; his commentary on Galen's Ars Parva was translated by Gerardo Cremonese. However, he is better known for providing the most detailed description of the supernova now known as SN 1006, the brightest stellar event in recorded history, which he observed in the year 1006. This was written in a commentary on Ptolemy's work Tetrabiblos. He was later cited by European authors as Haly, or Haly Abenrudian. According to Alistair Cameron Crombie he also contributed to the theory of induction. He engaged in a celebrated polemic against another physician, Ibn Butlan of Baghdad.

New!!: Star and Ali ibn Ridwan · See more »

Alpha particle

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.

New!!: Star and Alpha particle · See more »

Altair

Altair, also designated Alpha Aquilae (α Aquilae, abbreviated Alpha Aql, α Aql), is the brightest star in the constellation of Aquila and the twelfth brightest star in the night sky.

New!!: Star and Altair · See more »

Ancient Greece

Ancient Greece was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 13th–9th centuries BC to the end of antiquity (AD 600).

New!!: Star and Ancient Greece · See more »

Ancient Greek astronomy

Greek astronomy is astronomy written in the Greek language in classical antiquity.

New!!: Star and Ancient Greek astronomy · See more »

Ancient Greek philosophy

Ancient Greek philosophy arose in the 6th century BC and continued throughout the Hellenistic period and the period in which Ancient Greece was part of the Roman Empire.

New!!: Star and Ancient Greek philosophy · See more »

Ancient Greek religion

Ancient Greek religion encompasses the collection of beliefs, rituals, and mythology originating in ancient Greece in the form of both popular public religion and cult practices.

New!!: Star and Ancient Greek religion · See more »

Andromeda Galaxy

The Andromeda Galaxy, also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780 kiloparsecs (2.5 million light-years) from Earth, and the nearest major galaxy to the Milky Way.

New!!: Star and Andromeda Galaxy · See more »

Angelo Secchi

Fr.

New!!: Star and Angelo Secchi · See more »

Angular diameter

The angular diameter, angular size, apparent diameter, or apparent size is an angular measurement describing how large a sphere or circle appears from a given point of view.

New!!: Star and Angular diameter · See more »

Angular momentum

In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum.

New!!: Star and Angular momentum · See more »

Annie Jump Cannon

Annie Jump Cannon (December 11, 1863 – April 13, 1941) was an American astronomer whose cataloging work was instrumental in the development of contemporary stellar classification.

New!!: Star and Annie Jump Cannon · See more »

Apparent magnitude

The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.

New!!: Star and Apparent magnitude · See more »

Arabic

Arabic (العَرَبِيَّة) or (عَرَبِيّ) or) is a Central Semitic language that first emerged in Iron Age northwestern Arabia and is now the lingua franca of the Arab world. It is named after the Arabs, a term initially used to describe peoples living from Mesopotamia in the east to the Anti-Lebanon mountains in the west, in northwestern Arabia, and in the Sinai peninsula. Arabic is classified as a macrolanguage comprising 30 modern varieties, including its standard form, Modern Standard Arabic, which is derived from Classical Arabic. As the modern written language, Modern Standard Arabic is widely taught in schools and universities, and is used to varying degrees in workplaces, government, and the media. The two formal varieties are grouped together as Literary Arabic (fuṣḥā), which is the official language of 26 states and the liturgical language of Islam. Modern Standard Arabic largely follows the grammatical standards of Classical Arabic and uses much of the same vocabulary. However, it has discarded some grammatical constructions and vocabulary that no longer have any counterpart in the spoken varieties, and has adopted certain new constructions and vocabulary from the spoken varieties. Much of the new vocabulary is used to denote concepts that have arisen in the post-classical era, especially in modern times. During the Middle Ages, Literary Arabic was a major vehicle of culture in Europe, especially in science, mathematics and philosophy. As a result, many European languages have also borrowed many words from it. Arabic influence, mainly in vocabulary, is seen in European languages, mainly Spanish and to a lesser extent Portuguese, Valencian and Catalan, owing to both the proximity of Christian European and Muslim Arab civilizations and 800 years of Arabic culture and language in the Iberian Peninsula, referred to in Arabic as al-Andalus. Sicilian has about 500 Arabic words as result of Sicily being progressively conquered by Arabs from North Africa, from the mid 9th to mid 10th centuries. Many of these words relate to agriculture and related activities (Hull and Ruffino). Balkan languages, including Greek and Bulgarian, have also acquired a significant number of Arabic words through contact with Ottoman Turkish. Arabic has influenced many languages around the globe throughout its history. Some of the most influenced languages are Persian, Turkish, Spanish, Urdu, Kashmiri, Kurdish, Bosnian, Kazakh, Bengali, Hindi, Malay, Maldivian, Indonesian, Pashto, Punjabi, Tagalog, Sindhi, and Hausa, and some languages in parts of Africa. Conversely, Arabic has borrowed words from other languages, including Greek and Persian in medieval times, and contemporary European languages such as English and French in modern times. Classical Arabic is the liturgical language of 1.8 billion Muslims and Modern Standard Arabic is one of six official languages of the United Nations. All varieties of Arabic combined are spoken by perhaps as many as 422 million speakers (native and non-native) in the Arab world, making it the fifth most spoken language in the world. Arabic is written with the Arabic alphabet, which is an abjad script and is written from right to left, although the spoken varieties are sometimes written in ASCII Latin from left to right with no standardized orthography.

New!!: Star and Arabic · See more »

Aristyllus

Aristyllus (Ἀρίστυλλος; fl. c. 261 BC) was a Greek astronomer, presumably of the school of Timocharis (c. 300 BC).

New!!: Star and Aristyllus · See more »

Asterism (astronomy)

In observational astronomy, an asterism is a popular known pattern or group of stars that are recognised in the night sky.

New!!: Star and Asterism (astronomy) · See more »

Astrology

Astrology is the study of the movements and relative positions of celestial objects as a means for divining information about human affairs and terrestrial events.

New!!: Star and Astrology · See more »

Astronomer

An astronomer is a scientist in the field of astronomy who concentrates their studies on a specific question or field outside the scope of Earth.

New!!: Star and Astronomer · See more »

Astronomical constant

An astronomical constant is a physical constant used in astronomy.

New!!: Star and Astronomical constant · See more »

Astronomical object

An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.

New!!: Star and Astronomical object · See more »

Astronomical spectroscopy

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.

New!!: Star and Astronomical spectroscopy · See more »

Astronomical unit

The astronomical unit (symbol: au, ua, or AU) is a unit of length, roughly the distance from Earth to the Sun.

New!!: Star and Astronomical unit · See more »

Astronomy

Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.

New!!: Star and Astronomy · See more »

Astronomy in the medieval Islamic world

Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language.

New!!: Star and Astronomy in the medieval Islamic world · See more »

Asymptotic giant branch

The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars.

New!!: Star and Asymptotic giant branch · See more »

Atacama Large Millimeter Array

The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of radio telescopes in the Atacama Desert of northern Chile.

New!!: Star and Atacama Large Millimeter Array · See more »

Atomic nucleus

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.

New!!: Star and Atomic nucleus · See more »

Avempace

Avempace (– 1138) is the Latinate form of Ibn Bâjja (ابن باجه), full name Abû Bakr Muḥammad Ibn Yaḥyà ibn aṣ-Ṣâ’igh at-Tûjîbî Ibn Bâjja al-Tujibi (أبو بكر محمد بن يحيى بن الصائغ), was an Arab Andalusian polymath: his writings include works regarding astronomy, physics, and music, as well as philosophy, medicine, botany, and poetry.

New!!: Star and Avempace · See more »

Babylon

Babylon (KA2.DIĜIR.RAKI Bābili(m); Aramaic: בבל, Babel; بَابِل, Bābil; בָּבֶל, Bavel; ܒܒܠ, Bāwēl) was a key kingdom in ancient Mesopotamia from the 18th to 6th centuries BC.

New!!: Star and Babylon · See more »

Babylonian astronomy

The history of astronomy in Mesopotamia, and the world, begins with the Sumerians who developed the earliest writing system—known as cuneiform—around 3500–3200 BC.

New!!: Star and Babylonian astronomy · See more »

Babylonian star catalogues

Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia.

New!!: Star and Babylonian star catalogues · See more »

Bad Astronomy

Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax" is a non-fiction book by the American astronomer Phil Plait, also known as "the Bad Astronomer".

New!!: Star and Bad Astronomy · See more »

Bayer designation

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.

New!!: Star and Bayer designation · See more »

Beryllium

Beryllium is a chemical element with symbol Be and atomic number 4.

New!!: Star and Beryllium · See more »

Beta particle

A beta particle, also called beta ray or beta radiation, (symbol β) is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay.

New!!: Star and Beta particle · See more »

Betelgeuse

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.

New!!: Star and Betelgeuse · See more »

Big Bang

The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution.

New!!: Star and Big Bang · See more »

Binary star

A binary star is a star system consisting of two stars orbiting around their common barycenter.

New!!: Star and Binary star · See more »

Binding energy

Binding energy (also called separation energy) is the minimum energy required to disassemble a system of particles into separate parts.

New!!: Star and Binding energy · See more »

Black dwarf

A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light.

New!!: Star and Black dwarf · See more »

Black hole

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.

New!!: Star and Black hole · See more »

Blue dwarf (red-dwarf stage)

A blue dwarf is a predicted class of star that develops from a red dwarf after it has exhausted much of its hydrogen fuel supply.

New!!: Star and Blue dwarf (red-dwarf stage) · See more »

Blue straggler

A blue straggler is a main-sequence star in an open or globular cluster that is more luminous and bluer than stars at the main-sequence turn-off point for the cluster.

New!!: Star and Blue straggler · See more »

Blue supergiant star

Blue supergiant stars are hot luminous stars, referred to scientifically as OB supergiants.

New!!: Star and Blue supergiant star · See more »

Bok globule

In astronomy, Bok globules are isolated and relatively small dark nebulae, containing dense cosmic dust and gas from which star formation may take place.

New!!: Star and Bok globule · See more »

Book of Fixed Stars

The Book of Fixed Stars (كتاب صور الكواكب) is an astronomical text written by Abd al-Rahman al-Sufi (Azophi) around 964.

New!!: Star and Book of Fixed Stars · See more »

Brightness

Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light.

New!!: Star and Brightness · See more »

British Library

The British Library is the national library of the United Kingdom and the largest national library in the world by number of items catalogued.

New!!: Star and British Library · See more »

Brocchi's Cluster

Collinder 399 (Cr 399) is a random grouping of stars located in the constellation Vulpecula near the border with Sagitta.

New!!: Star and Brocchi's Cluster · See more »

Brown dwarf

Brown dwarfs are substellar objects that occupy the mass range between the heaviest gas giant planets and the lightest stars, having masses between approximately 13 to 75–80 times that of Jupiter, or approximately to about.

New!!: Star and Brown dwarf · See more »

Business

Business is the activity of making one's living or making money by producing or buying and selling products (goods and services).

New!!: Star and Business · See more »

Cambridge University Press

Cambridge University Press (CUP) is the publishing business of the University of Cambridge.

New!!: Star and Cambridge University Press · See more »

Canopus

Canopus, also designated Alpha Carinae (α Carinae, abbreviated Alpha Car, α Car), is the brightest star in the southern constellation of Carina, and the second-brightest star in the night-time sky, after Sirius.

New!!: Star and Canopus · See more »

Carbon

Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.

New!!: Star and Carbon · See more »

Carbon-12

Carbon-12 is the more abundant of the two stable isotopes of carbon (Carbon-13 being the other), amounting to 98.93% of the element carbon; its abundance is due to the triple-alpha process by which it is created in stars.

New!!: Star and Carbon-12 · See more »

Carbon-burning process

The carbon-burning process or carbon fusion is a set of nuclear fusion reactions that take place in the cores of massive stars (at least 8 \beginsmallmatrixM_\odot\endsmallmatrix at birth) that combines carbon into other elements.

New!!: Star and Carbon-burning process · See more »

Cataclysmic variable star

Cataclysmic variable stars (CV) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state.

New!!: Star and Cataclysmic variable star · See more »

Catalysis

Catalysis is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalysthttp://goldbook.iupac.org/C00876.html, which is not consumed in the catalyzed reaction and can continue to act repeatedly.

New!!: Star and Catalysis · See more »

Cecilia Payne-Gaposchkin

Cecilia Helena Payne-Gaposchkin (May 10, 1900 – December 7, 1979) was a British–American astronomer and astrophysicist who, in 1925, proposed in her Ph.D. thesis an explanation for the composition of stars in terms of the relative abundances of hydrogen and helium.

New!!: Star and Cecilia Payne-Gaposchkin · See more »

Celestial navigation

Celestial navigation, also known as astronavigation, is the ancient and modern practice of position fixing that enables a navigator to transition through a space without having to rely on estimated calculations, or dead reckoning, to know their position.

New!!: Star and Celestial navigation · See more »

Celestial spheres

The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others.

New!!: Star and Celestial spheres · See more »

Centimetre–gram–second system of units

The centimetre–gram–second system of units (abbreviated CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time.

New!!: Star and Centimetre–gram–second system of units · See more »

Centre de données astronomiques de Strasbourg

The Centre de Données astronomiques de Strasbourg (CDS; English translation: Strasbourg Astronomical Data Center) is a data hub which collects and distributes astronomical information.

New!!: Star and Centre de données astronomiques de Strasbourg · See more »

Cepheid variable

A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.

New!!: Star and Cepheid variable · See more »

Chemical element

A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).

New!!: Star and Chemical element · See more »

Chemically peculiar star

In astrophysics, chemically peculiar stars (CP stars) are stars with distinctly unusual metal abundances, at least in their surface layers.

New!!: Star and Chemically peculiar star · See more »

Chinese astronomy

Astronomy in China has a long history, beginning from the Shang Dynasty (Chinese Bronze Age).

New!!: Star and Chinese astronomy · See more »

Christmas

Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.

New!!: Star and Christmas · See more »

Christmas and holiday season

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.

New!!: Star and Christmas and holiday season · See more »

Christmas Eve

Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.

New!!: Star and Christmas Eve · See more »

Christmas traditions

Christmas traditions vary from country to country.

New!!: Star and Christmas traditions · See more »

Chromium

Chromium is a chemical element with symbol Cr and atomic number 24.

New!!: Star and Chromium · See more »

Chromosphere

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.

New!!: Star and Chromosphere · See more »

Civilization

A civilization or civilisation (see English spelling differences) is any complex society characterized by urban development, social stratification imposed by a cultural elite, symbolic systems of communication (for example, writing systems), and a perceived separation from and domination over the natural environment.

New!!: Star and Civilization · See more »

CNO cycle

The CNO cycle (for carbon–nitrogen–oxygen) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction.

New!!: Star and CNO cycle · See more »

Color index

In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature.

New!!: Star and Color index · See more »

Common envelope

In astronomy, a common envelope (CE) is gas that contains a binary star system.

New!!: Star and Common envelope · See more »

Compact star

In astronomy, the term "compact star" (or "compact object") refers collectively to white dwarfs, neutron stars, and black holes.

New!!: Star and Compact star · See more »

Concentration

In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture.

New!!: Star and Concentration · See more »

Conjunction (astronomy)

In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth.

New!!: Star and Conjunction (astronomy) · See more »

Constellation

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.

New!!: Star and Constellation · See more »

Contact binary

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.

New!!: Star and Contact binary · See more »

Convection

Convection is the heat transfer due to bulk movement of molecules within fluids such as gases and liquids, including molten rock (rheid).

New!!: Star and Convection · See more »

Convection zone

A convection zone, convective zone or convective region of a star is a layer which is unstable to convection.

New!!: Star and Convection zone · See more »

Corona

A corona (Latin, 'crown') is an aura of plasma that surrounds the Sun and other stars.

New!!: Star and Corona · See more »

Coronal loop

Coronal loops form the basic structure of the lower corona and transition region of the Sun.

New!!: Star and Coronal loop · See more »

Cosmic dust

Cosmic dust, also called extraterrestrial dust or space dust, is dust which exists in outer space, as well as all over planet Earth.

New!!: Star and Cosmic dust · See more »

Cosmology in medieval Islam

Islamic cosmology is the cosmology of Islamic societies.

New!!: Star and Cosmology in medieval Islam · See more »

Cosmos Redshift 7

Cosmos Redshift 7 (also known as COSMOS Redshift 7, Galaxy Cosmos Redshift 7, Galaxy CR7 or CR7) is a high-redshift Lyman-alpha emitter galaxy (meaning CR7 is one of the oldest, most distant galaxies), in the constellation Sextans, about 12.9 billion light travel distance years from Earth, reported to contain the first stars (first generation; Population III)—formed soon after the Big Bang during the reionisation epoch (redshift, z ∼ 6−7), when the Universe was about 800 million years old—to have provided the chemical elements (like oxygen, nitrogen, carbon, calcium and iron) needed for the later formation of planets and life as it is known.

New!!: Star and Cosmos Redshift 7 · See more »

Crab Nebula

The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant in the constellation of Taurus.

New!!: Star and Crab Nebula · See more »

Degenerate matter

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.

New!!: Star and Degenerate matter · See more »

Democritus

Democritus (Δημόκριτος, Dēmókritos, meaning "chosen of the people") was an Ancient Greek pre-Socratic philosopher primarily remembered today for his formulation of an atomic theory of the universe.

New!!: Star and Democritus · See more »

Density

The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.

New!!: Star and Density · See more »

Deuterium

Deuterium (or hydrogen-2, symbol or, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other being protium, or hydrogen-1).

New!!: Star and Deuterium · See more »

Doppler effect

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.

New!!: Star and Doppler effect · See more »

Dynamo theory

In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field.

New!!: Star and Dynamo theory · See more »

Earth

Earth is the third planet from the Sun and the only astronomical object known to harbor life.

New!!: Star and Earth · See more »

Ecliptic

The ecliptic is the circular path on the celestial sphere that the Sun follows over the course of a year; it is the basis of the ecliptic coordinate system.

New!!: Star and Ecliptic · See more »

Edmond Halley

Edmond (or Edmund) Halley, FRS (–) was an English astronomer, geophysicist, mathematician, meteorologist, and physicist.

New!!: Star and Edmond Halley · See more »

Edward Charles Pickering

Prof Edward Charles Pickering FRS(For) HFRSE (July 19, 1846 – February 3, 1919) was an American astronomer and physicist and the older brother to William Henry Pickering.

New!!: Star and Edward Charles Pickering · See more »

Effective temperature

The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation.

New!!: Star and Effective temperature · See more »

Egyptian astronomy

Egyptian astronomy begins in prehistoric times, in the Predynastic Period.

New!!: Star and Egyptian astronomy · See more »

Electromagnetic radiation

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.

New!!: Star and Electromagnetic radiation · See more »

Electromagnetic spectrum

The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.

New!!: Star and Electromagnetic spectrum · See more »

Electron capture

Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shell.

New!!: Star and Electron capture · See more »

Electronvolt

In physics, the electronvolt (symbol eV, also written electron-volt and electron volt) is a unit of energy equal to approximately joules (symbol J).

New!!: Star and Electronvolt · See more »

Energy flux

Energy flux is the rate of transfer of energy through a surface.

New!!: Star and Energy flux · See more »

Epicurus

Epicurus (Ἐπίκουρος, Epíkouros, "ally, comrade"; 341–270 BC) was an ancient Greek philosopher who founded a school of philosophy now called Epicureanism.

New!!: Star and Epicurus · See more »

Epsilon Indi

Epsilon Indi (ε Indi, ε Ind) is a star system approximately 12 light-years from Earth in the constellation of Indus consisting of a K-type main-sequence star, ε Indi A, and two brown dwarfs, ε Indi Ba and ε Indi Bb, in a wide orbit around it.

New!!: Star and Epsilon Indi · See more »

Eta Carinae

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.

New!!: Star and Eta Carinae · See more »

Exoplanet

An exoplanet or extrasolar planet is a planet outside our solar system.

New!!: Star and Exoplanet · See more »

Extinction (astronomy)

In astronomy, extinction is the absorption and scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observer.

New!!: Star and Extinction (astronomy) · See more »

Fairfield University

Fairfield University is a private Jesuit Catholic research university located in the coastal town of Fairfield, Connecticut.

New!!: Star and Fairfield University · See more »

Fakhr al-Din al-Razi

Fakhr al-Dīn al-Rāzī or Fakhruddin Razi (فخر الدين رازي) was an Iranian Sunni Muslim theologian and philosopher He was born in 1149 in Rey (in modern-day Iran), and died in 1209 in Herat (in modern-day Afghanistan).

New!!: Star and Fakhr al-Din al-Razi · See more »

First magnitude star

First magnitude stars are the brightest stars in the night sky, with a magnitude of -1, 0 and +1.

New!!: Star and First magnitude star · See more »

Flamsteed designation

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.

New!!: Star and Flamsteed designation · See more »

Flare star

A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes.

New!!: Star and Flare star · See more »

Frequency

Frequency is the number of occurrences of a repeating event per unit of time.

New!!: Star and Frequency · See more »

Friedrich Bessel

Friedrich Wilhelm Bessel (22 July 1784 – 17 March 1846) was a German astronomer, mathematician, physicist and geodesist.

New!!: Star and Friedrich Bessel · See more »

Friedrich Georg Wilhelm von Struve

Friedrich Georg Wilhelm von Struve (Василий Яковлевич Струве, trans. Vasily Yakovlevich Struve; 15 April 1793 –) was a German-Russian astronomer and geodesist from the famous Struve family.

New!!: Star and Friedrich Georg Wilhelm von Struve · See more »

Fuel

A fuel is any material that can be made to react with other substances so that it releases energy as heat energy or to be used for work.

New!!: Star and Fuel · See more »

G-type main-sequence star

A G-type main-sequence star (Spectral type: G-V), often (and imprecisely) called a yellow dwarf, or G dwarf star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.84 to 1.15 solar masses and surface temperature of between 5,300 and 6,000 K., G. M. H. J. Habets and J. R. W. Heintze, Astronomy and Astrophysics Supplement 46 (November 1981), pp.

New!!: Star and G-type main-sequence star · See more »

Galactic Center

The Galactic Center is the rotational center of the Milky Way.

New!!: Star and Galactic Center · See more »

Galactic Disc

The Galactic Disc is a component of disc galaxies, such as spiral galaxies and lenticular galaxies.

New!!: Star and Galactic Disc · See more »

Galaxy

A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.

New!!: Star and Galaxy · See more »

Gamma ray

A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.

New!!: Star and Gamma ray · See more »

Gas giant

A gas giant is a giant planet composed mainly of hydrogen and helium.

New!!: Star and Gas giant · See more »

Geminiano Montanari

Geminiano Montanari. Geminiano Montanari (June 1, 1633 – October 13, 1687) was an Italian astronomer, lens-maker, and proponent of the experimental approach to science.

New!!: Star and Geminiano Montanari · See more »

Giant star

A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature.

New!!: Star and Giant star · See more »

Giordano Bruno

Giordano Bruno (Iordanus Brunus Nolanus; 1548 – 17 February 1600), born Filippo Bruno, was an Italian Dominican friar, philosopher, mathematician, poet, and cosmological theorist.

New!!: Star and Giordano Bruno · See more »

Globular cluster

A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.

New!!: Star and Globular cluster · See more »

Gradient

In mathematics, the gradient is a multi-variable generalization of the derivative.

New!!: Star and Gradient · See more »

Gravitational collapse

Gravitational collapse is the contraction of an astronomical object due to the influence of its own gravity, which tends to draw matter inward toward the center of gravity.

New!!: Star and Gravitational collapse · See more »

Gravitational constant

The gravitational constant (also known as the "universal gravitational constant", the "Newtonian constant of gravitation", or the "Cavendish gravitational constant"), denoted by the letter, is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton's law of universal gravitation and in Albert Einstein's general theory of relativity.

New!!: Star and Gravitational constant · See more »

Gravitational microlensing

Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect.

New!!: Star and Gravitational microlensing · See more »

Gravity

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.

New!!: Star and Gravity · See more »

Greek mythology

Greek mythology is the body of myths and teachings that belong to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices.

New!!: Star and Greek mythology · See more »

Gregorian calendar

The Gregorian calendar is the most widely used civil calendar in the world.

New!!: Star and Gregorian calendar · See more »

H II region

An H II region or HII region is a region of interstellar atomic hydrogen that is ionized.

New!!: Star and H II region · See more »

Hayashi track

The Hayashi track is a luminosity–temperature relationship obeyed by infant stars of less than in the pre-main-sequence phase (PMS phase) of stellar evolution.

New!!: Star and Hayashi track · See more »

HD 140283

HD 140283, informally nicknamed the Methuselah star, is a metal-poor subgiant star about 200 light years away from the Earth in the constellation Libra, specifically toward Ophiuchus.

New!!: Star and HD 140283 · See more »

Heat transfer

Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems.

New!!: Star and Heat transfer · See more »

Heliosphere

The heliosphere is the bubble-like region of space dominated by the Sun, which extends far beyond the orbit of Pluto.

New!!: Star and Heliosphere · See more »

Helium

Helium (from lit) is a chemical element with symbol He and atomic number 2.

New!!: Star and Helium · See more »

Helium flash

A helium flash is a very brief thermal runaway nuclear fusion of large quantities of helium into carbon through the triple-alpha process in the core of low mass stars (between 0.8 solar masses and 2.0) during their red giant phase (the Sun is predicted to experience a flash 1.2 billion years after it leaves the main sequence).

New!!: Star and Helium flash · See more »

Helium-3

Helium-3 (He-3, also written as 3He, see also helion) is a light, non-radioactive isotope of helium with two protons and one neutron (common helium having two protons and two neutrons).

New!!: Star and Helium-3 · See more »

Helium-4

Helium-4 is a non-radioactive isotope of the element helium.

New!!: Star and Helium-4 · See more »

Henyey track

The Henyey track is a path taken by pre-main-sequence stars with masses >0.5 Solar mass in the Hertzsprung–Russell diagram after the end of Hayashi track.

New!!: Star and Henyey track · See more »

Herbig Ae/Be star

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.

New!!: Star and Herbig Ae/Be star · See more »

Herbig–Haro object

Herbig–Haro (HH) objects are turbulent looking patches of nebulosity associated with newborn stars.

New!!: Star and Herbig–Haro object · See more »

Hertzsprung–Russell diagram

The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

New!!: Star and Hertzsprung–Russell diagram · See more »

Hipparchus

Hipparchus of Nicaea (Ἵππαρχος, Hipparkhos) was a Greek astronomer, geographer, and mathematician.

New!!: Star and Hipparchus · See more »

Horizontal branch

The horizontal branch (HB) is a stage of stellar evolution that immediately follows the red giant branch in stars whose masses are similar to the Sun's.

New!!: Star and Horizontal branch · See more »

Human eye

The human eye is an organ which reacts to light and pressure.

New!!: Star and Human eye · See more »

Hydrogen

Hydrogen is a chemical element with symbol H and atomic number 1.

New!!: Star and Hydrogen · See more »

Hydrogen line

The hydrogen line, 21-centimeter line or H I line refers to the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms.

New!!: Star and Hydrogen line · See more »

Hydrostatic equilibrium

In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when the flow velocity at each point is constant over time.

New!!: Star and Hydrostatic equilibrium · See more »

Hypergiant

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.

New!!: Star and Hypergiant · See more »

IAU Working Group on Star Names

The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community.

New!!: Star and IAU Working Group on Star Names · See more »

Infrared

Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.

New!!: Star and Infrared · See more »

Interacting galaxy

Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another.

New!!: Star and Interacting galaxy · See more »

Interferometry

Interferometry is a family of techniques in which waves, usually electromagnetic waves, are superimposed causing the phenomenon of interference in order to extract information.

New!!: Star and Interferometry · See more »

International Astronomical Union

The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy.

New!!: Star and International Astronomical Union · See more »

International Star Registry

The International Star Registry (ISR) is an organization founded in 1979 for the purpose of giving people the novelty of officially naming stars.

New!!: Star and International Star Registry · See more »

International System of Units

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.

New!!: Star and International System of Units · See more »

Interstellar medium

In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy.

New!!: Star and Interstellar medium · See more »

Inverse beta decay

Inverse beta decay, commonly abbreviated to IBD, is a nuclear reaction involving electron antineutrino scattering off a proton, creating a positron and a neutron.

New!!: Star and Inverse beta decay · See more »

Ion

An ion is an atom or molecule that has a non-zero net electrical charge (its total number of electrons is not equal to its total number of protons).

New!!: Star and Ion · See more »

Iron

Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.

New!!: Star and Iron · See more »

Isaac Newton

Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, astronomer, theologian, author and physicist (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time, and a key figure in the scientific revolution.

New!!: Star and Isaac Newton · See more »

Isis (journal)

Isis is a quarterly peer-reviewed academic journal published by the University of Chicago Press.

New!!: Star and Isis (journal) · See more »

Islamic calendar

The Islamic, Muslim, or Hijri calendar (التقويم الهجري at-taqwīm al-hijrī) is a lunar calendar consisting of 12 months in a year of 354 or 355 days.

New!!: Star and Islamic calendar · See more »

Isotopes of beryllium

Beryllium (4Be) has 12 known isotopes, but only one of these isotopes is stable and a primordial nuclide.

New!!: Star and Isotopes of beryllium · See more »

Isotopes of hydrogen

Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted 1H, 2H, and 3H.

New!!: Star and Isotopes of hydrogen · See more »

Jeans instability

In stellar physics, the Jeans instability causes the collapse of interstellar gas clouds and subsequent star formation.

New!!: Star and Jeans instability · See more »

Johann Bayer

Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer).

New!!: Star and Johann Bayer · See more »

John Flamsteed

John Flamsteed FRS (19 August 1646 – 31 December 1719) was an English astronomer and the first Astronomer Royal.

New!!: Star and John Flamsteed · See more »

John Herschel

Sir John Frederick William Herschel, 1st Baronet (7 March 1792 – 11 May 1871) was an English polymath, mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint, and did botanical work.

New!!: Star and John Herschel · See more »

Joseph von Fraunhofer

Joseph Ritter von Fraunhofer (6 March 1787 – 7 June 1826) was a Bavarian physicist and optical lens manufacturer.

New!!: Star and Joseph von Fraunhofer · See more »

Jupiter

Jupiter is the fifth planet from the Sun and the largest in the Solar System.

New!!: Star and Jupiter · See more »

Karl Schwarzschild

Karl Schwarzschild (October 9, 1873 – May 11, 1916) was a German physicist and astronomer.

New!!: Star and Karl Schwarzschild · See more »

Kassites

The Kassites were people of the ancient Near East, who controlled Babylonia after the fall of the Old Babylonian Empire c. 1531 BC and until c. 1155 BC (short chronology).

New!!: Star and Kassites · See more »

Kelvin

The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.

New!!: Star and Kelvin · See more »

Large Magellanic Cloud

The Large Magellanic Cloud (LMC) is a satellite galaxy of the Milky Way.

New!!: Star and Large Magellanic Cloud · See more »

Latin

Latin (Latin: lingua latīna) is a classical language belonging to the Italic branch of the Indo-European languages.

New!!: Star and Latin · See more »

Latitude

In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth's surface.

New!!: Star and Latitude · See more »

LBV 1806-20

LBV 1806-20 is a candidate luminous blue variable (LBV) and likely binary star located nearly 40,000 light-years from the Sun, towards the center of the Milky Way.

New!!: Star and LBV 1806-20 · See more »

Life

Life is a characteristic that distinguishes physical entities that do have biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased, or because they never had such functions and are classified as inanimate.

New!!: Star and Life · See more »

Light-year

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.

New!!: Star and Light-year · See more »

Limb darkening

Limb darkening is an optical effect seen in stars (including the Sun), where the center part of the disk appears brighter than the edge or limb of the image.

New!!: Star and Limb darkening · See more »

List of Arabic star names

This is a list of traditional Arabic names for stars.

New!!: Star and List of Arabic star names · See more »

List of largest stars

Below is an ordered list of the largest stars currently known by radius.

New!!: Star and List of largest stars · See more »

Lists of stars

The following are lists of stars.

New!!: Star and Lists of stars · See more »

Lithium

Lithium (from lit) is a chemical element with symbol Li and atomic number 3.

New!!: Star and Lithium · See more »

Local Group

The Local Group is the galaxy group that includes the Milky Way.

New!!: Star and Local Group · See more »

Logarithmic scale

A logarithmic scale is a nonlinear scale used when there is a large range of quantities.

New!!: Star and Logarithmic scale · See more »

Luminosity

In astronomy, luminosity is the total amount of energy emitted per unit of time by a star, galaxy, or other astronomical object.

New!!: Star and Luminosity · See more »

Lunar eclipse

A lunar eclipse occurs when the Moon passes directly behind Earth and into its shadow.

New!!: Star and Lunar eclipse · See more »

Luyten 726-8

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.

New!!: Star and Luyten 726-8 · See more »

MACS J1149 Lensed Star 1

MACS J1149 Lensed Star 1, also known as Icarus,Other names include LS1, MACS J1149 LS1, MACS J1149 Lensed Star 1 (LS1) and MACS J1149+2223 Lensed Star 1 is a blue supergiant observed through a gravitational lens.

New!!: Star and MACS J1149 Lensed Star 1 · See more »

Magnetic field

A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.

New!!: Star and Magnetic field · See more »

Main sequence

In astronomy, the main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness.

New!!: Star and Main sequence · See more »

Mars

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.

New!!: Star and Mars · See more »

Mass

Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.

New!!: Star and Mass · See more »

Mass–energy equivalence

In physics, mass–energy equivalence states that anything having mass has an equivalent amount of energy and vice versa, with these fundamental quantities directly relating to one another by Albert Einstein's famous formula: E.

New!!: Star and Mass–energy equivalence · See more »

Maunder Minimum

The Maunder Minimum, also known as the "prolonged sunspot minimum", is the name used for the period around 1645 to 1715 during which sunspots became exceedingly rare, as was then noted by solar observers.

New!!: Star and Maunder Minimum · See more »

Mercury (planet)

Mercury is the smallest and innermost planet in the Solar System.

New!!: Star and Mercury (planet) · See more »

Mesopotamia

Mesopotamia is a historical region in West Asia situated within the Tigris–Euphrates river system, in modern days roughly corresponding to most of Iraq, Kuwait, parts of Northern Saudi Arabia, the eastern parts of Syria, Southeastern Turkey, and regions along the Turkish–Syrian and Iran–Iraq borders.

New!!: Star and Mesopotamia · See more »

Metallicity

In astronomy, metallicity is used to describe the abundance of elements present in an object that are heavier than hydrogen or helium.

New!!: Star and Metallicity · See more »

Milky Way

The Milky Way is the galaxy that contains our Solar System.

New!!: Star and Milky Way · See more »

Minute and second of arc

A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.

New!!: Star and Minute and second of arc · See more »

Mira variable

Mira variables ("Mira", Latin, adj. - feminine form of adjective "wonderful"), named for the prototype star Mira, are a class of pulsating variable stars characterized by very red colours, pulsation periods longer than 100 days, and amplitudes greater than one magnitude in infrared and 2.5 magnitude at visual wavelengths.

New!!: Star and Mira variable · See more »

Molecular cloud

A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit the formation of molecules, most commonly molecular hydrogen (H2).

New!!: Star and Molecular cloud · See more »

Monthly Notices of the Royal Astronomical Society

Monthly Notices of the Royal Astronomical Society (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics.

New!!: Star and Monthly Notices of the Royal Astronomical Society · See more »

Moon

The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.

New!!: Star and Moon · See more »

Mount Wilson Observatory

The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States.

New!!: Star and Mount Wilson Observatory · See more »

Mu Leonis

Mu Leonis (μ Leonis, abbreviated Mu Leo, μ Leo), also named Rasalas, is a star in the constellation of Leo.

New!!: Star and Mu Leonis · See more »

Mythology

Mythology refers variously to the collected myths of a group of people or to the study of such myths.

New!!: Star and Mythology · See more »

Names of large numbers

This article lists and discusses the usage and derivation of names of large numbers, together with their possible extensions.

New!!: Star and Names of large numbers · See more »

Nature (journal)

Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.

New!!: Star and Nature (journal) · See more »

Nebula

A nebula (Latin for "cloud" or "fog"; pl. nebulae, nebulæ, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases.

New!!: Star and Nebula · See more »

Neon

Neon is a chemical element with symbol Ne and atomic number 10.

New!!: Star and Neon · See more »

Neon-burning process

The neon-burning process (nuclear decay) is a set of nuclear fusion reactions that take place in massive stars (at least 8 Solar masses).

New!!: Star and Neon-burning process · See more »

Neptune

Neptune is the eighth and farthest known planet from the Sun in the Solar System.

New!!: Star and Neptune · See more »

Neutrino

A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.

New!!: Star and Neutrino · See more »

Neutron star

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!!: Star and Neutron star · See more »

New Year

New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.

New!!: Star and New Year · See more »

New Year's Day

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.

New!!: Star and New Year's Day · See more »

New Year's Eve

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.

New!!: Star and New Year's Eve · See more »

New York City Department of Consumer Affairs

The New York City Department of Consumer Affairs (DCA) is an agency of the Government of New York City.

New!!: Star and New York City Department of Consumer Affairs · See more »

NGC 6397

NGC 6397, also known as Caldwell 86, is a globular cluster in the constellation Ara.

New!!: Star and NGC 6397 · See more »

Night sky

The term night sky, usually associated with astronomy from Earth, refers to the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon.

New!!: Star and Night sky · See more »

Nova

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.

New!!: Star and Nova · See more »

Nth root

In mathematics, an nth root of a number x, where n is usually assumed to be a positive integer, is a number r which, when raised to the power n yields x: where n is the degree of the root.

New!!: Star and Nth root · See more »

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei).

New!!: Star and Nuclear fission · See more »

Nuclear fusion

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).

New!!: Star and Nuclear fusion · See more »

O-type star

An O-type star is a hot, blue-white star of spectral type O in the Yerkes classification system employed by astronomers.

New!!: Star and O-type star · See more »

Observable universe

The observable universe is a spherical region of the Universe comprising all matter that can be observed from Earth at the present time, because electromagnetic radiation from these objects has had time to reach Earth since the beginning of the cosmological expansion.

New!!: Star and Observable universe · See more »

Observatory

An observatory is a location used for observing terrestrial or celestial events.

New!!: Star and Observatory · See more »

Occultation

An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer.

New!!: Star and Occultation · See more »

Omicron Velorum

Omicron Velorum (ο Vel, ο Velorum) is a star in the constellation Vela.

New!!: Star and Omicron Velorum · See more »

Opacity (optics)

Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light.

New!!: Star and Opacity (optics) · See more »

Open cluster

An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age.

New!!: Star and Open cluster · See more »

Orbit

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.

New!!: Star and Orbit · See more »

Orbital elements

Orbital elements are the parameters required to uniquely identify a specific orbit.

New!!: Star and Orbital elements · See more »

Orion (constellation)

Orion is a prominent constellation located on the celestial equator and visible throughout the world.

New!!: Star and Orion (constellation) · See more »

Orion Nebula

The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated in the Milky Way, being south of Orion's Belt in the constellation of Orion.

New!!: Star and Orion Nebula · See more »

Outer space

Outer space, or just space, is the expanse that exists beyond the Earth and between celestial bodies.

New!!: Star and Outer space · See more »

Outline of astronomy

The following outline is provided as an overview of and topical guide to astronomy: Astronomy – studies the universe beyond Earth, including its formation and development, and the evolution, physics, chemistry, meteorology, and motion of celestial objects (such as galaxies, planets, etc.) and phenomena that originate outside the atmosphere of Earth (such as the cosmic background radiation).

New!!: Star and Outline of astronomy · See more »

Oxygen

Oxygen is a chemical element with symbol O and atomic number 8.

New!!: Star and Oxygen · See more »

Oxygen-burning process

The oxygen-burning process is a set of nuclear fusion reactions that take place in massive stars that have used up the lighter elements in their cores.

New!!: Star and Oxygen-burning process · See more »

Parallax

Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines.

New!!: Star and Parallax · See more »

Particle radiation

Particle radiation is the radiation of energy by means of fast-moving subatomic particles.

New!!: Star and Particle radiation · See more »

Persian people

The Persians--> are an Iranian ethnic group that make up over half the population of Iran.

New!!: Star and Persian people · See more »

Photoelectric effect

The photoelectric effect is the emission of electrons or other free carriers when light shines on a material.

New!!: Star and Photoelectric effect · See more »

Photograph

A photograph or photo is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic medium such as a CCD or a CMOS chip.

New!!: Star and Photograph · See more »

Photographic magnitude

Before the advent of photometers which accurately measure the brightness of astronomical objects, the apparent magnitude of an object was obtained by taking a picture of it with a camera.

New!!: Star and Photographic magnitude · See more »

Photometer

A photometer, generally, is an instrument that measures light intensity or the optical properties of solutions or surfaces.

New!!: Star and Photometer · See more »

Photon

The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles).

New!!: Star and Photon · See more »

Photosphere

The photosphere is a star's outer shell from which light is radiated.

New!!: Star and Photosphere · See more »

Planck (spacecraft)

Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013, which mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infra-red frequencies, with high sensitivity and small angular resolution.

New!!: Star and Planck (spacecraft) · See more »

Planet

A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.

New!!: Star and Planet · See more »

Planetary nebula

A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

New!!: Star and Planetary nebula · See more »

Planetary system

A planetary system is a set of gravitationally bound non-stellar objects in or out of orbit around a star or star system.

New!!: Star and Planetary system · See more »

Plasma (physics)

Plasma (Henry George Liddell, Robert Scott, A Greek English Lexicon, on Perseus) is one of the four fundamental states of matter, and was first described by chemist Irving Langmuir in the 1920s.

New!!: Star and Plasma (physics) · See more »

Polymath

A polymath (πολυμαθής,, "having learned much,"The term was first recorded in written English in the early seventeenth century Latin: uomo universalis, "universal man") is a person whose expertise spans a significant number of different subject areas—such a person is known to draw on complex bodies of knowledge to solve specific problems.

New!!: Star and Polymath · See more »

Positron

The positron or antielectron is the antiparticle or the antimatter counterpart of the electron.

New!!: Star and Positron · See more »

Power (physics)

In physics, power is the rate of doing work, the amount of energy transferred per unit time.

New!!: Star and Power (physics) · See more »

Pre-main-sequence star

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.

New!!: Star and Pre-main-sequence star · See more »

Pressure gradient

In atmospheric science (meteorology, climatology and related fields), the pressure gradient (typically of air, more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location.

New!!: Star and Pressure gradient · See more »

Procyon

Procyon, also designated Alpha Canis Minoris (α Canis Minoris, abbreviated Alpha CMi, α CMi), is the brightest star in the constellation of Canis Minor.

New!!: Star and Procyon · See more »

Proper motion

Proper motion is the astronomical measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distant stars.

New!!: Star and Proper motion · See more »

Proton

| magnetic_moment.

New!!: Star and Proton · See more »

Proton–proton chain reaction

The proton–proton chain reaction is one of the two (known) sets of fusion reactions by which stars convert hydrogen to helium.

New!!: Star and Proton–proton chain reaction · See more »

Protoplanetary disk

A protoplanetary disk is a rotating circumstellar disk of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star.

New!!: Star and Protoplanetary disk · See more »

Protostar

A protostar is a very young star that is still gathering mass from its parent molecular cloud.

New!!: Star and Protostar · See more »

Proxima Centauri

Proxima Centauri, or Alpha Centauri C, is a red dwarf, a small low-mass star, about from the Sun in the constellation of Centaurus.

New!!: Star and Proxima Centauri · See more »

Ptolemy

Claudius Ptolemy (Κλαύδιος Πτολεμαῖος, Klaúdios Ptolemaîos; Claudius Ptolemaeus) was a Greco-Roman mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology.

New!!: Star and Ptolemy · See more »

Pulsar

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.

New!!: Star and Pulsar · See more »

QCD matter

Quark matter or QCD matter refers to any of a number of theorized phases of matter whose degrees of freedom include quarks and gluons.

New!!: Star and QCD matter · See more »

Quantum mechanics

Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.

New!!: Star and Quantum mechanics · See more »

R Doradus

R Doradus (HD 29712 or P Doradus) is the name of a red giant Mira variable star in the far-southern constellation Dorado, although visually it appears more closely associated with the constellation Reticulum.

New!!: Star and R Doradus · See more »

R136

R136 (formally known as RMC 136 from the Radcliffe Observatory Magellanic Clouds catalogue) is the central concentration of stars in the NGC 2070 star cluster, which lies at the centre of the Tarantula Nebula in the Large Magellanic Cloud.

New!!: Star and R136 · See more »

Radial velocity

The radial velocity of an object with respect to a given point is the rate of change of the distance between the object and the point.

New!!: Star and Radial velocity · See more »

Radiant energy

In physics, and in particular as measured by radiometry, radiant energy is the energy of electromagnetic and gravitational radiation.

New!!: Star and Radiant energy · See more »

Radiation

In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

New!!: Star and Radiation · See more »

Radiation pressure

Radiation pressure is the pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field.

New!!: Star and Radiation pressure · See more »

Radiation zone

A radiation zone, radiative zone or radiative region is a layer of a star's interior where energy is primarily transported toward the exterior by means of radiative diffusion and thermal conduction, rather than by convection.

New!!: Star and Radiation zone · See more »

Radio frequency

Radio frequency (RF) refers to oscillatory change in voltage or current in a circuit, waveguide or transmission line in the range extending from around twenty thousand times per second to around three hundred billion times per second, roughly between the upper limit of audio and the lower limit of infrared.

New!!: Star and Radio frequency · See more »

Radius

In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.

New!!: Star and Radius · See more »

Rare-earth element

A rare-earth element (REE) or rare-earth metal (REM), as defined by IUPAC, is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides, as well as scandium and yttrium.

New!!: Star and Rare-earth element · See more »

Red clump

The red clump is a clustering of red giants in the Hertzsprung–Russell diagram at around 5,000 K and absolute magnitude (MV) +0.5, slightly hotter than most red-giant-branch stars of the same luminosity.

New!!: Star and Red clump · See more »

Red dwarf

A red dwarf (or M dwarf) is a small and relatively cool star on the main sequence, of M spectral type.

New!!: Star and Red dwarf · See more »

Red giant

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.

New!!: Star and Red giant · See more »

Red supergiant star

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.

New!!: Star and Red supergiant star · See more »

Red-giant branch

The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution.

New!!: Star and Red-giant branch · See more »

Redshift

In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.

New!!: Star and Redshift · See more »

Refraction

Refraction is the change in direction of wave propagation due to a change in its transmission medium.

New!!: Star and Refraction · See more »

Regulation

Regulation is an abstract concept of management of complex systems according to a set of rules and trends.

New!!: Star and Regulation · See more »

Reionization

In the field of Big Bang theory, and cosmology, reionization is the process that caused the matter in the universe to reionize after the lapse of the "dark ages".

New!!: Star and Reionization · See more »

Richard Bentley

Richard Bentley (27 January 1662 – 14 July 1742) was an English classical scholar, critic, and theologian.

New!!: Star and Richard Bentley · See more »

Rigel

Rigel, also designated Beta Orionis (β Orionis, abbreviated Beta Ori, β Ori), is generally the seventh-brightest star in the night sky and the brightest star in the constellation of Orion—though periodically it is outshone within the constellation by the variable Betelgeuse.

New!!: Star and Rigel · See more »

Right ascension

Right ascension (abbreviated RA; symbol) is the angular distance measured only eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point above the earth in question.

New!!: Star and Right ascension · See more »

Roche lobe

The Roche lobe (or Roche limit) is the region around a star in a binary system within which orbiting material is gravitationally bound to that star.

New!!: Star and Roche lobe · See more »

Roman mythology

Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans.

New!!: Star and Roman mythology · See more »

Rotation

A rotation is a circular movement of an object around a center (or point) of rotation.

New!!: Star and Rotation · See more »

Saturn

Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.

New!!: Star and Saturn · See more »

Second

The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each.

New!!: Star and Second · See more »

Semi-major and semi-minor axes

In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the widest points of the perimeter.

New!!: Star and Semi-major and semi-minor axes · See more »

Sherburne Wesley Burnham

Sherburne Wesley Burnham (December 12, 1838 – March 11, 1921) was an American astronomer.

New!!: Star and Sherburne Wesley Burnham · See more »

Shock wave

In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance.

New!!: Star and Shock wave · See more »

Sidereal time

Sidereal time is a timekeeping system that astronomers use to locate celestial objects.

New!!: Star and Sidereal time · See more »

Silicon

Silicon is a chemical element with symbol Si and atomic number 14.

New!!: Star and Silicon · See more »

Silicon-burning process

In astrophysics, silicon burning is a very brief sequence of nuclear fusion reactions that occur in massive stars with a minimum of about 8-11 solar masses.

New!!: Star and Silicon-burning process · See more »

Sirius

Sirius (a romanization of Greek Σείριος, Seirios,."glowing" or "scorching") is a star system and the brightest star in the Earth's night sky.

New!!: Star and Sirius · See more »

SN 1006

SN 1006 was a supernova that is likely the brightest observed stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus.

New!!: Star and SN 1006 · See more »

SN 1054

SN 1054 is a supernova that was first observed on 4 July 1054, and remained visible for around two years.

New!!: Star and SN 1054 · See more »

SN 185

SN 185 was a transient astronomical event observed in AD 185, likely a supernova.

New!!: Star and SN 185 · See more »

Solar calendar

A solar calendar is a calendar whose dates indicate the season or almost equivalently the position of the apparent position of the sun in relative to the stars.

New!!: Star and Solar calendar · See more »

Solar eclipse

A solar eclipse (as seen from the planet Earth) is a type of eclipse that occurs when the Moon passes between the Sun and Earth, and when the Moon fully or partially blocks ("occults") the Sun.

New!!: Star and Solar eclipse · See more »

Solar flare

A solar flare is a sudden flash of increased Sun's brightness, usually observed near its surface.

New!!: Star and Solar flare · See more »

Solar luminosity

The solar luminosity,, is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun.

New!!: Star and Solar luminosity · See more »

Solar mass

The solar mass is a standard unit of mass in astronomy, equal to approximately.

New!!: Star and Solar mass · See more »

Solar radius

Solar radius is a unit of distance used to express the size of stars in astronomy.

New!!: Star and Solar radius · See more »

Solar wind

The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona.

New!!: Star and Solar wind · See more »

Space Shuttle

The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration (NASA), as part of the Space Shuttle program.

New!!: Star and Space Shuttle · See more »

Space.com

Space.com is a space and astronomy news website.

New!!: Star and Space.com · See more »

Spectral line

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.

New!!: Star and Spectral line · See more »

Spectroscopy

Spectroscopy is the study of the interaction between matter and electromagnetic radiation.

New!!: Star and Spectroscopy · See more »

Spheroid

A spheroid, or ellipsoid of revolution, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters.

New!!: Star and Spheroid · See more »

Spicule (solar physics)

In solar physics, a spicule is a dynamic jet of about 500 km diameter in the chromosphere of the Sun.

New!!: Star and Spicule (solar physics) · See more »

Spiral galaxy

Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae(pp. 124–151) and, as such, form part of the Hubble sequence.

New!!: Star and Spiral galaxy · See more »

Stanford Encyclopedia of Philosophy

The Stanford Encyclopedia of Philosophy (SEP) combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users.

New!!: Star and Stanford Encyclopedia of Philosophy · See more »

Star catalogue

A star catalogue (Commonwealth English) or star catalog (American English), is an astronomical catalogue that lists stars.

New!!: Star and Star catalogue · See more »

Star chart

A star chart or star map, also called a sky chart or sky map, is a map of the night sky.

New!!: Star and Star chart · See more »

Star clock

A star clock (or nocturnal) is a method of using the stars to determine the time.

New!!: Star and Star clock · See more »

Star cluster

Star clusters are groups of stars.

New!!: Star and Star cluster · See more »

Star count

Star counts are bookkeeping surveys of stars and the statistical and geometrical methods used to correct the survey data for bias.

New!!: Star and Star count · See more »

Star formation

Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars.

New!!: Star and Star formation · See more »

Star system

A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction.

New!!: Star and Star system · See more »

Starburst galaxy

A starburst galaxy is a galaxy undergoing an exceptionally high rate of star formation, as compared to the long-term average rate of star formation in the galaxy or the star formation rate observed in most other galaxies.

New!!: Star and Starburst galaxy · See more »

Stars and planetary systems in fiction

The planetary systems of stars other than the Sun and the Solar System are a staple element in many works of the science fiction genre.

New!!: Star and Stars and planetary systems in fiction · See more »

Starspot

Starspots are stellar phenomena.

New!!: Star and Starspot · See more »

Stellar association

A stellar association is a very loose star cluster, looser than both open clusters and globular clusters.

New!!: Star and Stellar association · See more »

Stellar atmosphere

The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone.

New!!: Star and Stellar atmosphere · See more »

Stellar classification

In astronomy, stellar classification is the classification of stars based on their spectral characteristics.

New!!: Star and Stellar classification · See more »

Stellar designations and names

Designations and names of stars (and other celestial bodies) are currently primarily mediated in the scientific community by the International Astronomical Union (IAU), a de facto authority.

New!!: Star and Stellar designations and names · See more »

Stellar dynamics

Stellar dynamics is the branch of astrophysics which describes in a statistical way the collective motions of stars subject to their mutual gravity.

New!!: Star and Stellar dynamics · See more »

Stellar evolution

Stellar evolution is the process by which a star changes over the course of time.

New!!: Star and Stellar evolution · See more »

Stellar kinematics

In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.

New!!: Star and Stellar kinematics · See more »

Stellar mass

Stellar mass is a phrase that is used by astronomers to describe the mass of a star.

New!!: Star and Stellar mass · See more »

Stellar nucleosynthesis

Stellar nucleosynthesis is the theory explaining the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions between atoms within the stars.

New!!: Star and Stellar nucleosynthesis · See more »

Stellar population

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.

New!!: Star and Stellar population · See more »

Stellar wind

A stellar wind is a flow of gas ejected from the upper atmosphere of a star.

New!!: Star and Stellar wind · See more »

Students for the Exploration and Development of Space

Students for the Exploration and Development of Space (SEDS) is an international student organization whose purpose is to promote space exploration and development through educational and engineering projects.

New!!: Star and Students for the Exploration and Development of Space · See more »

Sun

The Sun is the star at the center of the Solar System.

New!!: Star and Sun · See more »

Sunspot

Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas.

New!!: Star and Sunspot · See more »

Supergiant star

Supergiants are among the most massive and most luminous stars.

New!!: Star and Supergiant star · See more »

Supernova

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.

New!!: Star and Supernova · See more »

Supernova nucleosynthesis

Supernova nucleosynthesis is a theory of the nucleosynthesis of the natural abundances of the chemical elements in supernova explosions, advanced as the nucleosynthesis of elements from carbon to nickel in massive stars by Fred Hoyle in 1954.

New!!: Star and Supernova nucleosynthesis · See more »

Supernova remnant

A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova.

New!!: Star and Supernova remnant · See more »

Surface gravity

The surface gravity, g, of an astronomical or other object is the gravitational acceleration experienced at its surface.

New!!: Star and Surface gravity · See more »

T Tauri star

T Tauri stars (TTS) are a class of variable stars associated with youth.

New!!: Star and T Tauri star · See more »

Telescope

A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).

New!!: Star and Telescope · See more »

The Astrophysical Journal

The Astrophysical Journal, often abbreviated ApJ (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler.

New!!: Star and The Astrophysical Journal · See more »

The New York Times

The New York Times (sometimes abbreviated as The NYT or The Times) is an American newspaper based in New York City with worldwide influence and readership.

New!!: Star and The New York Times · See more »

Thermal equilibrium

Two physical systems are in thermal equilibrium if there are no net flow of thermal energy between them when they are connected by a path permeable to heat.

New!!: Star and Thermal equilibrium · See more »

Thermonuclear fusion

Thermonuclear fusion is a way to achieve nuclear fusion by using extremely high temperatures.

New!!: Star and Thermonuclear fusion · See more »

Timocharis

Timocharis of Alexandria (Τιμόχαρις or Τιμοχάρης, gen. Τιμοχάρους; c. 320–260 BC) was a Greek astronomer and philosopher.

New!!: Star and Timocharis · See more »

Triple-alpha process

The triple-alpha process is a set of nuclear fusion reactions by which three helium-4 nuclei (alpha particles) are transformed into carbon.

New!!: Star and Triple-alpha process · See more »

Twinkle, Twinkle, Little Star

"Twinkle, Twinkle, Little Star" is a popular English lullaby.

New!!: Star and Twinkle, Twinkle, Little Star · See more »

Twinkling

Twinkling, or scintillation, is a generic term for variations in apparent brightness or position of a distant luminous object viewed through a medium.

New!!: Star and Twinkling · See more »

Tycho Brahe

Tycho Brahe (born Tyge Ottesen Brahe;. He adopted the Latinized form "Tycho Brahe" (sometimes written Tÿcho) at around age fifteen. The name Tycho comes from Tyche (Τύχη, meaning "luck" in Greek, Roman equivalent: Fortuna), a tutelary deity of fortune and prosperity of ancient Greek city cults. He is now generally referred to as "Tycho," as was common in Scandinavia in his time, rather than by his surname "Brahe" (a spurious appellative form of his name, Tycho de Brahe, only appears much later). 14 December 154624 October 1601) was a Danish nobleman, astronomer, and writer known for his accurate and comprehensive astronomical and planetary observations.

New!!: Star and Tycho Brahe · See more »

Type Ia supernova

A type Ia supernova (read "type one-a") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf.

New!!: Star and Type Ia supernova · See more »

Ultraviolet

Ultraviolet (UV) is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.

New!!: Star and Ultraviolet · See more »

Unfair business practices

Unfair business practices encompass fraud, misrepresentation, and oppressive or unconscionable acts or practices by business, often against consumers and are prohibited by law in many countries.

New!!: Star and Unfair business practices · See more »

Universe

The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.

New!!: Star and Universe · See more »

University of California

The University of California (UC) is a public university system in the US state of California.

New!!: Star and University of California · See more »

Uranus

Uranus is the seventh planet from the Sun.

New!!: Star and Uranus · See more »

Vacuum chamber

A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump.

New!!: Star and Vacuum chamber · See more »

Vega

Vega, also designated Alpha Lyrae (α Lyrae, abbreviated Alpha Lyr or α Lyr), is the brightest star in the constellation of Lyra, the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus.

New!!: Star and Vega · See more »

Venus

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.

New!!: Star and Venus · See more »

Very Large Telescope

The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile.

New!!: Star and Very Large Telescope · See more »

Virgo Cluster

The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the constellation Virgo.

New!!: Star and Virgo Cluster · See more »

Virgo Supercluster

The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which in turn contains the Milky Way and Andromeda galaxies.

New!!: Star and Virgo Supercluster · See more »

Wavelength

In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.

New!!: Star and Wavelength · See more »

White dwarf

A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.

New!!: Star and White dwarf · See more »

William Herschel

Frederick William Herschel, (Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer, composer and brother of fellow astronomer Caroline Herschel, with whom he worked.

New!!: Star and William Herschel · See more »

Wolf–Rayet star

Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of highly ionised helium and nitrogen or carbon.

New!!: Star and Wolf–Rayet star · See more »

X-ray

X-rays make up X-radiation, a form of electromagnetic radiation.

New!!: Star and X-ray · See more »

X-ray burster

X-ray bursters are one class of X-ray binary stars exhibiting periodic and rapid increases in luminosity (typically a factor of 10 or greater) that peak in the X-ray regime of the electromagnetic spectrum.

New!!: Star and X-ray burster · See more »

Yale University Press

Yale University Press is a university press associated with Yale University.

New!!: Star and Yale University Press · See more »

Zeta Ophiuchi

Zeta Ophiuchi (ζ Oph, ζ Ophiuchi) is a star located in the constellation of Ophiuchus.

New!!: Star and Zeta Ophiuchi · See more »

Zeta Ursae Majoris

Mizar is a 2nd magnitude star in the handle of the Big Dipper asterism in the constellation of Ursa Major.

New!!: Star and Zeta Ursae Majoris · See more »

Zij

A zīj (زيج) is an Islamic astronomical book that tabulates parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets.

New!!: Star and Zij · See more »

14 Herculis

14 Herculis or 14 Her is the Flamsteed designation of a K-type main-sequence star approximately 57 light-years away in the constellation Hercules.

New!!: Star and 14 Herculis · See more »

2018

2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.

New!!: Star and 2018 · See more »

2019

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.

New!!: Star and 2019 · See more »

2MASS J0523-1403

2MASS J0523-1403 is a very-low-mass red dwarf about 40 light years from Earth in the southern constellation of Lepus.

New!!: Star and 2MASS J0523-1403 · See more »

61 Cygni

61 Cygni Not to be confused with 16 Cygni, a more distant system containing two G-type stars harboring the gas giant planet 16 Cygni Bb.

New!!: Star and 61 Cygni · See more »

Redirects here:

Intermediate mass star, Intermediate mass stars, Intermediate star, Massive star, Star fission, Stars, Stellar diameter, Stellar radius, Stellum, Wishstar.

References

[1] https://en.wikipedia.org/wiki/Star

OutgoingIncoming
Hey! We are on Facebook now! »