172 relations: Abd al-Rahman al-Sufi, Absolute magnitude, Amateur astronomy, American Institute of Physics, Andromeda (constellation), Andromeda–Milky Way collision, Angular diameter, Annual Review of Astronomy and Astrophysics, Apparent magnitude, Apsis, Astronomy (magazine), Astronomy Picture of the Day, Astrophysics (journal), Astrophysics and Space Science, Autumn, Barred spiral galaxy, BBC News, Binary star, Binoculars, Black hole, Blueshift, Book of Fixed Stars, Brady Haran, Bulge (astronomy), California Institute of Technology, Cartwheel Galaxy, Cavendish Astrophysics Group, Celestial coordinate system, Cepheid variable, Chandra X-ray Observatory, Charles Messier, Color index, Cosmic dust, Dark matter, Declination, Degree (angle), Disc galaxy, Doppler effect, Dwarf galaxy, Earth, Edwin Hubble, Elliptical galaxy, Ernst Öpik, European Space Agency, Flocculent spiral galaxy, Frequency, Galactic Disc, Galactic halo, Galaxies in fiction, Galaxy, ..., Galaxy color–magnitude diagram, Galaxy group, Galaxy merger, Galaxy rotation curve, Globular cluster, Gravitational microlensing, Great Debate (astronomy), H I region, H II region, Harlow Shapley, Harvard–Smithsonian Center for Astrophysics, Heber Doust Curtis, Hipparcos, Hubble Space Telescope, Hydrogen, Hydrogen line, Immanuel Kant, Infrared Processing and Analysis Center, Infrared Space Observatory, International Astronomical Union, Interstellar medium, Isaac Roberts, Jan Oort, Jodrell Bank Observatory, John E. Baldwin, Light pollution, Light-year, Linearity, List of galaxies, List of Messier objects, Local Group, Lowell Observatory, Luminosity, Luminous infrared galaxy, Magnitude (astronomy), Mayall II, Mega-, Messier 110, Messier 32, Messier object, Metallicity, Microquasar, Milky Way, Minute and second of arc, Monthly Notices of the Royal Astronomical Society, Mount Wilson Observatory, Naked eye, NASA, Nature (journal), Neil Gehrels Swift Observatory, Neutron star, New General Catalogue, New Scientist, NGC 206, Northern Hemisphere, Nova, Omega Centauri, Orbital eccentricity, Orbital inclination, Orders of magnitude (numbers), Parsec, Persian Empire, Philosophical Transactions of the Royal Society, Principal Galaxies Catalogue, Protogalaxy, Publications of the Astronomical Society of the Pacific, Radio astronomy, Red clump, Red giant, Right ascension, Ring galaxy, Robert Hanbury Brown, Satellite galaxy, Second Cambridge Catalogue of Radio Sources, Simon Marius, Sirius, SN 1885A, Solar mass, Solar System, Sombrero Galaxy, Southern Hemisphere, Space.com, Spectral line, Spectroscopy, Spectrum, Spiral galaxy, Spitzer Space Telescope, Spring (season), Star chart, Star cluster, Star formation, Starburst galaxy, Stellar classification, Students for the Exploration and Development of Space, Supernova, Surface brightness fluctuation, Telescope, The Astronomical Journal, The Astronomy and Astrophysics Review, The Astrophysical Journal, Tidal force, Tip of the red-giant branch, Triangulum Galaxy, Trigonometry, Universe, Universe Today, University of California, Santa Cruz, Uppsala General Catalogue, Velocity dispersion, Very Large Array, Very Long Baseline Array, Vesto Slipher, W. M. Keck Observatory, Walter Baade, Wavelength, William Herschel, William Huggins, William Parsons, 3rd Earl of Rosse, XMM-Newton, Yale University Press, Zenith, 2MASS. Expand index (122 more) » « Shrink index
'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.
Absolute magnitude is a measure of the luminosity of a celestial object, on a logarithmic astronomical magnitude scale.
Amateur astronomy is a hobby whose participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes.
The American Institute of Physics (AIP) promotes science, the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies.
Andromeda is one of the 48 constellations listed by the 2nd-century Greco-Roman astronomer Ptolemy and remains one of the 88 modern constellations.
The Andromeda–Milky Way collision is a galactic collision predicted to occur in about 4 billion years between two galaxies in the Local Group—the Milky Way (which contains the Solar System and Earth) and the Andromeda Galaxy.
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.
The Annual Review of Astronomy and Astrophysics is an annual peer reviewed scientific journal published by Annual Reviews.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
An apsis (ἁψίς; plural apsides, Greek: ἁψῖδες) is an extreme point in the orbit of an object.
Astronomy is a monthly American magazine about astronomy.
Astronomy Picture of the Day (APOD) is a website provided by NASA and Michigan Technological University (MTU).
Astrophysics is a peer-reviewed scientific journal of astrophysics published by Springer.
Astrophysics and Space Science is a bimonthly peer-reviewed scientific journal covering astronomy, astrophysics, and space science and astrophysical aspects of astrobiology.
Autumn, also known as fall in American and Canadian English, is one of the four temperate seasons.
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars.
BBC News is an operational business division of the British Broadcasting Corporation (BBC) responsible for the gathering and broadcasting of news and current affairs.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
Binoculars or field glasses are two telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects.
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.
A blueshift is any decrease in wavelength, with a corresponding increase in frequency, of an electromagnetic wave; the opposite effect is referred to as redshift.
The Book of Fixed Stars (كتاب صور الكواكب) is an astronomical text written by Abd al-Rahman al-Sufi (Azophi) around 964.
Brady John Haran (born 18 June 1976) is an Australian-born British independent filmmaker and video journalist who is known for his educational videos and documentary films produced for BBC News and his YouTube channels, the most notable being Periodic Videos and Numberphile.
In astronomy, a bulge is a tightly packed group of stars within a larger formation.
The California Institute of Technology (abbreviated Caltech)The university itself only spells its short form as "Caltech"; other spellings such as.
The Cartwheel Galaxy (also known as ESO 350-40) is a lenticular galaxy and ring galaxy about 500 million light-years away in the constellation Sculptor.
The Cavendish Astrophysics Group (formerly the Radio Astronomy Group) is based at the Cavendish Laboratory at the University of Cambridge.
In astronomy, a celestial coordinate system is a system for specifying positions of celestial objects: satellites, planets, stars, galaxies, and so on.
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.
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999.
Charles Messier (26 June 1730 – 12 April 1817) was a French astronomer most notable for publishing an astronomical catalogue consisting of nebulae and star clusters that came to be known as the 110 "Messier objects".
Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.
The Christmas season, also called the festive season, or the holiday season (mainly in the U.S. and Canada; often simply called the holidays),, is an annually recurring period recognized in many Western and Western-influenced countries that is generally considered to run from late November to early January.
Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.
Christmas traditions vary from country to country.
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.
Cosmic dust, also called extraterrestrial dust or space dust, is dust which exists in outer space, as well as all over planet Earth.
Dark matter is a theorized form of matter that is thought to account for approximately 80% of the matter in the universe, and about a quarter of its total energy density.
In astronomy, declination (abbreviated dec; symbol δ) is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle.
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
A disc galaxy is a galaxy characterized by a disc, a flattened circular volume of stars.
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.
A dwarf galaxy is a small galaxy composed of about 100 million up to several billion stars, a small number compared to the Milky Way's 200–400 billion stars.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer.
An elliptical galaxy is a type of galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless image.
Ernst Julius Öpik (– 10 September 1985) was an Estonian astronomer and astrophysicist who spent the second half of his career (1948–1981) at the Armagh Observatory in Northern Ireland.
The European Space Agency (ESA; Agence spatiale européenne, ASE; Europäische Weltraumorganisation) is an intergovernmental organisation of 22 member states dedicated to the exploration of space.
A flocculent spiral galaxy is a type of spiral galaxy.
Frequency is the number of occurrences of a repeating event per unit of time.
The Galactic Disc is a component of disc galaxies, such as spiral galaxies and lenticular galaxies.
A galactic halo is an extended, roughly spherical component of a galaxy which extends beyond the main, visible component.
Galaxies other than the Milky Way are popular settings for creators of science fiction, particularly those working with broad-scale space opera settings.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.
The galaxy color–magnitude diagram shows the relationship between absolute magnitude (a measure of luminosity) and mass of galaxies.
A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxies larger than groups that are first-order clustering are called galaxy clusters.
Galaxy mergers can occur when two (or more) galaxies collide.
The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's centre.
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect.
The Great Debate, also called the Shapley–Curtis Debate, was held on 26 April 1920 at the Smithsonian Museum of Natural History, between the astronomers Harlow Shapley and Heber Curtis.
An HI region or H I region (read H one) is a cloud in the interstellar medium composed of neutral atomic hydrogen (HI), in addition to the local abundance of helium and other elements.
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized.
Harlow Shapley (November 2, 1885 – October 20, 1972) was a 20th-century American scientist, head of the Harvard College Observatory (1921–1952), and political activist during the latter New Deal and Fair Deal.
The Harvard–Smithsonian Center for Astrophysics (CfA) is a research institute which carries out a broad program of research in astronomy, astrophysics, earth and space sciences, and science education.
Heber Doust Curtis (June 27, 1872 – January 9, 1942) was an American astronomer.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
Hydrogen is a chemical element with symbol H and atomic number 1.
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.
Immanuel Kant (22 April 1724 – 12 February 1804) was a German philosopher who is a central figure in modern philosophy.
The Infrared Processing and Analysis Center (IPAC) provides science operations, data management, data archives and community support for astronomy and planetary science missions.
The Infrared Space Observatory (ISO) was a space telescope for infrared light designed and operated by the European Space Agency (ESA), in cooperation with ISAS (part of JAXA as of 2003) and NASA.
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.
In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy.
Isaac Roberts FRS (27 January 1829 – 17 July 1904) was a Welsh engineer and businessman best known for his work as an amateur astronomer, pioneering the field of astrophotography of nebulae.
Jan Hendrik Oort (or; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy.
The Jodrell Bank Observatory (originally the Jodrell Bank Experimental Station, then the Nuffield Radio Astronomy Laboratories from 1966 to 1999) is a British observatory that hosts a number of radio telescopes, and is part of the Jodrell Bank Centre for Astrophysics at the University of Manchester.
John Evan Baldwin FRS (–) was a British Astronomer who worked at the Cavendish Astrophysics Group (formerly Mullard Radio Astronomy Observatory) from 1954.
Light pollution, also known as photopollution, is the presence of anthropogenic light in the night environment.
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.
Linearity is the property of a mathematical relationship or function which means that it can be graphically represented as a straight line.
The following is a list of notable galaxies.
The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his "Catalogue des Nébuleuses et des Amas d'Étoiles" ("Catalogue of Nebulae and Star Clusters").
The Local Group is the galaxy group that includes the Milky Way.
Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States.
In astronomy, luminosity is the total amount of energy emitted per unit of time by a star, galaxy, or other astronomical object.
Luminous infrared galaxies or LIRGs are galaxies with luminosities, the measurement of brightness, above.
In astronomy, magnitude is a logarithmic measure of the brightness of an object in a defined passband, often in the visible or infrared spectrum, but sometimes across all wavelengths.
Mayall II, also known as NGC-224-G1, SKHB 1, GSC 2788:2139, HBK 0-1, M31GC J003247+393440 or Andromeda's Cluster, is a globular cluster orbiting M31, the Andromeda Galaxy.
Mega is a unit prefix in metric systems of units denoting a factor of one million (106 or 000).
Messier 110, also known as NGC 205, is a dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy.
Messier 32 (also known as NGC 221) is a dwarf "early-type" galaxy located about 2.65 million light-years from Earth, appearing in the constellation Andromeda.
The Messier objects are a set of 110 astronomical objects, of which 103 were included in lists published by French astronomer Charles Messier in 1771 and 1781.
In astronomy, metallicity is used to describe the abundance of elements present in an object that are heavier than hydrogen or helium.
A microquasar, the smaller version of a quasar, is a compact region surrounding a black hole with a mass several times that of our sun, and its companion star.
The Milky Way is the galaxy that contains our Solar System.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
Monthly Notices of the Royal Astronomical Society (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics.
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States.
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying or light-collecting optical instrument, such as a telescope or microscope.
The National Aeronautics and Space Administration (NASA) is an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and aerospace research.
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.
The Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Mission, is a NASA space telescope designed to detect gamma-ray bursts (GRBs).
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
The New General Catalogue of Nebulae and Clusters of Stars (abbreviated as NGC) is a catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888.
New Scientist, first published on 22 November 1956, is a weekly, English-language magazine that covers all aspects of science and technology.
NGC 206 is a bright star cloud in the Andromeda Galaxy.
New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.
New Year's Day, also called simply New Year's or New Year, is observed on January 1, the first day of the year on the modern Gregorian calendar as well as the Julian calendar.
In the Gregorian calendar, New Year's Eve (also known as Old Year's Day or Saint Sylvester's Day in many countries), the last day of the year, is on 31 December which is the seventh day of Christmastide.
The Northern Hemisphere is the half of Earth that is north of the Equator.
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.
Omega Centauri (ω Cen or NGC 5139) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in 1677.
The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.
Orbital inclination measures the tilt of an object's orbit around a celestial body.
This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantity and probabilities.
The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.
The Persian Empire (شاهنشاهی ایران, translit., lit. 'Imperial Iran') refers to any of a series of imperial dynasties that were centred in Persia/Iran from the 6th-century-BC Achaemenid Empire era to the 20th century AD in the Qajar dynasty era.
Philosophical Transactions, titled Philosophical Transactions of the Royal Society (often abbreviated as Phil. Trans.) from 1776, is a scientific journal published by the Royal Society.
The Catalogue of Principal Galaxies (PGC) is an astronomical catalog published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies.
In physical cosmology, a protogalaxy, which could also be called a "primeval galaxy", is a cloud of gas which is forming into a galaxy.
Publications of the Astronomical Society of the Pacific (often abbreviated as PASP in references and literature) is a monthly peer-reviewed scientific journal managed by the Astronomical Society of the Pacific.
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies.
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.
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.
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.
A ring galaxy is a galaxy with a circle-like appearance.
Robert Hanbury Brown, AC FRS (31 August 1916 – 16 January 2002) was a British astronomer and physicist born in Aruvankadu, India.
A satellite galaxy is a smaller companion galaxy that travels on bound orbits within the gravitational potential of a more massive and luminous host galaxy (also known as the primary galaxy).
The Second Cambridge Catalogue of Radio Sources (2C) was published in 1955 by John R Shakeshaft and colleagues.
Simon Marius (Latinized from German Simon Mayr; January 20, 1573 – January 5, 1625) was a German astronomer.
Sirius (a romanization of Greek Σείριος, Seirios,."glowing" or "scorching") is a star system and the brightest star in the Earth's night sky.
The solar mass is a standard unit of mass in astronomy, equal to approximately.
The Solar SystemCapitalization of the name varies.
The Sombrero Galaxy (also known as Messier Object 104, M104 or NGC 4594) is a spiral galaxy in the constellation Virgo located from Earth.
The Southern Hemisphere is the half of Earth that is south of the Equator.
Space.com is a space and astronomy news website.
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.
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
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.
The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003 and still operating as of 2018.
Spring is one of the four conventional temperate seasons, following winter and preceding summer.
A star chart or star map, also called a sky chart or sky map, is a map of the night sky.
Star clusters are groups of stars.
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.
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.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
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.
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.
Surface brightness fluctuation (SBF) is a secondary distance indicator used to estimate distances to galaxies.
A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).
The Astronomical Journal (often abbreviated AJ in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society and currently published by IOP Publishing.
The Astronomy and Astrophysics Review is a peer-reviewed scientific journal that is published quarterly by Springer Science+Business Media.
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.
The tidal force is an apparent force that stretches a body towards the center of mass of another body due to a gradient (difference in strength) in gravitational field from the other body; it is responsible for the diverse phenomena, including tides, tidal locking, breaking apart of celestial bodies and formation of ring systems within Roche limit, and in extreme cases, spaghettification of objects.
Tip of the red-giant branch (TRGB) is a primary distance indicator used in astronomy.
The Triangulum Galaxy is a spiral galaxy approximately 3 million light-years (ly) from Earth in the constellation Triangulum.
Trigonometry (from Greek trigōnon, "triangle" and metron, "measure") is a branch of mathematics that studies relationships involving lengths and angles of triangles.
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
Universe Today (UT) is a popular North American-based non-commercial space and astronomy news website.
The University of California, Santa Cruz (also known as UC Santa Cruz or UCSC), is a public research university and one of 10 campuses in the University of California system.
The Uppsala General Catalogue of Galaxies (UGC) is a catalogue of 12,921 galaxies visible from the northern hemisphere.
In astronomy, the velocity dispersion (σ) is the statistical dispersion of velocities about the mean velocity for a group of objects, such as an open cluster, globular cluster, galaxy, galaxy cluster, or supercluster.
The Karl G. Jansky Very Large Array (VLA) is a centimeter-wavelength radio astronomy observatory located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro.
The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the (LBO).
Vesto Melvin Slipher (November 11, 1875 – November 8, 1969) was an American astronomer who performed the first measurements of radial velocities for galaxies, providing the empirical basis for the expansion of the universe.
The W. M. Keck Observatory is a two-telescope astronomical observatory at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii.
Wilhelm Heinrich Walter Baade (March 24, 1893 – June 25, 1960) was a German astronomer who worked in the United States from 1931 to 1959.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
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.
Sir William Huggins (7 February 1824 – 12 May 1910) was an English astronomer best known for his pioneering work in astronomical spectroscopy together with his wife Margaret Lindsay Huggins.
William Parsons, 3rd Earl of Rosse HFRSE (17 June 1800 – 31 October 1867) was an Anglo-Irish astronomer who had several telescopes built.
XMM-Newton, also known as the High Throughput X-ray Spectroscopy Mission and the X-ray Multi-Mirror Mission, is an X-ray space observatory launched by the European Space Agency in December 1999 on an Ariane 5 rocket.
Yale University Press is a university press associated with Yale University.
The zenith is an imaginary point directly "above" a particular location, on the imaginary celestial sphere.
2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.
2019 (MMXIX) will be a common year starting on Tuesday of the Gregorian calendar, the 2019th year of the Common Era (CE) and Anno Domini (AD) designations, the 19th year of the 3rd millennium, the 19th year of the 21st century, and the 10th and last year of the 2010s decade.
The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in the infrared spectrum and one of the most ambitious such projects.
2C 56, 2MASX J00424433+4116074, 33 Andromedae, Andromeda (astronomy), Andromeda (galaxy), Andromeda galaxy, Andromedea, Andromenda, DA 21, GIN 801, Galaxy M31, Great Andromeda Nebula, Great Andromeda Spiral Galaxy, IRAS 00400+4059, IRC +40013, K79 1C, LEDA 2557, MCG+07-02-016, Messier 31, Messier Object 31, NGC 224, NGC224, PGC 2557, RAFGL 104, The Andromeda Galaxy, UGC 454, XSS J00425+4102, Z 0040.0+4100, Z 535-17.