142 relations: Aberration of light, Acronym, Adriaan Blaauw, Age of the universe, Apparent magnitude, Ariane (rocket family), Ariane 4, Arianespace, Asteroseismology, Astrium, Astrometry, Astronomical seeing, Atmosphere, Axial precession, Binary star, Bremen, Bristol, British Aerospace, Brown dwarf, Carl Zeiss AG, Carte du Ciel, Cartesian coordinate system, Catalogues of Fundamental Stars, Celestial sphere, Center of mass, Centre de données astronomiques de Strasbourg, Cepheid variable, Chandler wobble, Charge-coupled device, CNES, Correlation and dependence, Delft, Delta Scuti variable, Doppler effect, Double star, EADS CASA, Earth, Earth's rotation, Ecliptic, Effective temperature, ELA-2, Epoch (astronomy), European Space Agency, European Space Operations Centre, Exoplanet, François Mignard, Friedrichshafen, Gaia (spacecraft), Galactic halo, Galaxy, ..., Galaxy rotation curve, Gamma-ray burst, General relativity, Geocentric orbit, Geostationary orbit, Geostationary transfer orbit, Germany, Globular cluster, Gothenburg, Gould Belt, Gravitational lens, Gravity, Guiana Space Centre, Gyroscope, HD 209458, Hipparchus, Hubble Space Telescope, Hyades (star cluster), Hydrazine, Ice age, Image dissector, Inertial frame of reference, Initial mass function, International Celestial Reference System, Kourou, Least squares, Leiden, Light, Lobbying, Lutz–Kelker bias, Madrid, Marseille, Matra Marconi Space, MERLIN, Michael Perryman, Millennium Star Atlas, Minute and second of arc, Monthly Notices of the Royal Astronomical Society, Netherlands Institute for Space Research, Neuchâtel, Newton (unit), Oberkochen, Observatory of Strasbourg, Oort constants, Oort limit, Parallax, Parameterized post-Newtonian formalism, Photometric system, Photomultiplier, Pleiades, Proper motion, Quasar, Radial velocity, Red giant, Rheinmetall Air Defence, RR Lyrae variable, RUAG Space, S band, Satellite, Schmidt camera, Search for extraterrestrial intelligence, Sloan Digital Sky Survey, Space telescope, Special relativity, Spectroscopy, Speed, Spiral galaxy, Springer Science+Business Media, Standard error, Star, Star formation, Star system, Stellar association, Stellar classification, Stellar evolution, Stellar kinematics, Stellar structure, Subdwarf, Thales Alenia Space, Trigonometry, Tycho-2 Catalogue, UBV photometric system, United States Naval Observatory, Vélizy-Villacoublay, Very Large Array, Very-long-baseline interferometry, Vignetting, White dwarf, Wolf–Rayet star, Zürich, 2MASS, 3C 273. Expand index (92 more) » « Shrink index
The aberration of light (also referred to as astronomical aberration, stellar aberration, or velocity aberration) is an astronomical phenomenon which produces an apparent motion of celestial objects about their true positions, dependent on the velocity of the observer.
An acronym is a word or name formed as an abbreviation from the initial components in a phrase or a word, usually individual letters (as in NATO or laser) and sometimes syllables (as in Benelux).
Adriaan Blaauw (12 April 1914 – 1 December 2010) was a Dutch astronomer.
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
Ariane is a series of a European civilian expendable launch vehicles for space launch use.
The Ariane 4 was an expendable launch system, designed by the Centre national d'études spatiales while being manufactured and marketed by its subsidiary Arianespace.
Arianespace SA is a multinational company founded in 1980 as the world's first commercial launch service provider.
Asteroseismology or astroseismology is the study of oscillations in stars.
Astrium was an aerospace manufacturer subsidiary of the European Aeronautic Defence and Space Company (EADS) that provided civil and military space systems and services from 2006 to 2013.
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.
Astronomical seeing is the blurring and twinkling of astronomical objects like stars due to turbulent mixing in the Earth's atmosphere, causing variations of the optical refractive index.
An atmosphere is a layer or a set of layers of gases surrounding a planet or other material body, that is held in place by the gravity of that body.
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
The City Municipality of Bremen (Stadtgemeinde Bremen) is a Hanseatic city in northwestern Germany, which belongs to the Free Hanseatic City of Bremen (also called just "Bremen" for short), a federal state of Germany.
Bristol is a city and county in South West England with a population of 456,000.
British Aerospace plc (BAe) was a British aircraft, munitions and defence-systems manufacturer.
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.
Carl Zeiss, branded as ZEISS, is a German manufacturer of optical systems, industrial measurements and medical devices, founded in Jena, Germany in 1846 by optician Carl Zeiss.
The Carte du Ciel (literally, 'Map of the Sky') and the Astrographic Catalogue (or Astrographic Chart) were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue and map the positions of millions of stars as faint as 11th or 12th magnitude.
A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular directed lines, measured in the same unit of length.
The Catalogue of Fundamental Stars is a series of six astrometric catalogues of high precision positional data for a small selection of stars to define a celestial reference frame, which is a standard coordinate system for measuring positions of stars.
In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.
In physics, the center of mass of a distribution of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero, or the point where if a force is applied it moves in the direction of the force without rotating.
The Centre de Données astronomiques de Strasbourg (CDS; English translation: Strasbourg Astronomical Data Center) is a data hub which collects and distributes astronomical information.
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 Chandler wobble or variation of latitude is a small deviation in the Earth's axis of rotation relative to the solid earth, which was discovered by American astronomer Seth Carlo Chandler in 1891.
A charge-coupled device (CCD) is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value.
The Centre national d'études spatiales (CNES) (English: National Centre for Space Studies) is the French government space agency (administratively, a "public administration with industrial and commercial purpose").
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 statistics, dependence or association is any statistical relationship, whether causal or not, between two random variables or bivariate data.
Delft is a city and municipality in the province of South Holland, Netherlands.
A Delta Scuti variable (sometimes termed dwarf cepheid) is a variable star which exhibits variations in its luminosity due to both radial and non-radial pulsations of the star's surface.
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope.
EADS CASA was a Spanish aircraft manufacturer, previously Construcciones Aeronáuticas SA (CASA).
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
Earth's rotation is the rotation of Planet Earth around its own axis.
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.
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.
ELA-2, short for Ensemble de Lancement Ariane 2 (French for Ariane Launch Area 2), was a launch pad at the Centre Spatial Guyanais in French Guiana.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
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.
The European Space Operations Centre (ESOC) serves as the main mission control centre for the European Space Agency (ESA) and is located in Darmstadt, Germany.
An exoplanet or extrasolar planet is a planet outside our solar system.
François Mignard (born 1949) is a French astronomer who is the director of CERGA (Centre de recherches en géodynamique et astrométrie) of the Observatoire de la Côte d'Azur.
Friedrichshafen is an industrial city on the northern shoreline of Lake Constance (the Bodensee) in Southern Germany, near the borders of both Switzerland and Austria.
Gaia is a space observatory of the European Space Agency (ESA) designed for astrometry: measuring the positions and distances of stars with unprecedented precision.
A galactic halo is an extended, roughly spherical component of a galaxy which extends beyond the main, visible component.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.
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.
In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic explosions that have been observed in distant galaxies.
General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.
A geocentric orbit or Earth orbit involves any object orbiting Planet Earth, such as the Moon or artificial satellites.
A geostationary orbit, often referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit above Earth's equator and following the direction of Earth's rotation.
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a Hohmann transfer orbit—an elliptical orbit used to transfer between two circular orbits of different radii in the same plane—used to reach geosynchronous or geostationary orbit using high-thrust chemical engines.
Germany (Deutschland), officially the Federal Republic of Germany (Bundesrepublik Deutschland), is a sovereign state in central-western Europe.
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.
Gothenburg (abbreviated Gbg; Göteborg) is the second-largest city in Sweden and the fifth-largest in the Nordic countries.
The Gould Belt is a partial ring of stars in the Milky Way, about 3000 light years across, tilted toward the galactic plane by about 16 to 20 degrees.
A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer, that is capable of bending the light from the source as the light travels towards the observer.
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.
The Guiana Space Centre or, more commonly, Centre Spatial Guyanais (CSG) is a French and European spaceport to the northwest of Kourou in French Guiana.
A gyroscope (from Ancient Greek γῦρος gûros, "circle" and σκοπέω skopéō, "to look") is a device used for measuring or maintaining orientation and angular velocity.
HD 209458 is an 8th-magnitude star in the constellation Pegasus.
Hipparchus of Nicaea (Ἵππαρχος, Hipparkhos) was a Greek astronomer, geographer, and mathematician.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
The Hyades (Greek Ὑάδες, also known as Melotte 25 or Collinder 50) is the nearest open cluster and one of the best-studied star clusters.
Hydrazine is an inorganic compound with the chemical formula (also written), called diamidogen, archaically.
An ice age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.
An image dissector, also called a dissector tube, is a video camera tube in which photocathode emissions create an "electron image" which is then scanned to produce an electrical signal representing the visual image.
An inertial frame of reference in classical physics and special relativity is a frame of reference in which a body with zero net force acting upon it is not accelerating; that is, such a body is at rest or it is moving at a constant speed in a straight line.
In astronomy, the initial mass function (IMF) is an empirical function that describes the initial distribution of masses for a population of stars.
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU).
Kourou is a commune in French Guiana, an overseas region and department of France located in South America.
The method of least squares is a standard approach in regression analysis to approximate the solution of overdetermined systems, i.e., sets of equations in which there are more equations than unknowns.
Leiden (in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
Lobbying, persuasion, or interest representation is the act of attempting to influence the actions, policies, or decisions of officials in their daily life, most often legislators or members of regulatory agencies.
The Lutz–Kelker bias is a supposed systematic bias that results from the assumption that the number of observable stars increases with the square of the distance.
Madrid is the capital of Spain and the largest municipality in both the Community of Madrid and Spain as a whole.
Marseille (Provençal: Marselha), is the second-largest city of France and the largest city of the Provence historical region.
Matra Marconi Space (MMS) was a Franco-British aerospace company.
The Multi-Element Radio Linked Interferometer Network (MERLIN) is an interferometer array of radio telescopes spread across England.
Michael Perryman is a British astronomer, known for his work leading the Hipparcos and Gaia space astrometric projects.
The Millennium Star Atlas was constructed as a collaboration between a team at Sky & Telescope led by Roger Sinnott, and the European Space Agency's Hipparcos project, led by Michael Perryman.
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.
SRON Netherlands Institute for Space Research is the Dutch expertise institute for space research.
Neuchâtel, or Neuchatel; (neu(f) "new" and chatel "castle" (château); Neuenburg; Neuchâtel; Neuchâtel or Neufchâtel)The city was also called Neuchâtel-outre-Joux (Neuchâtel beyond Joux) to distinguish it from another Neuchâtel in Burgundy, now Neuchâtel-Urtière.
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 newton (symbol: N) is the International System of Units (SI) derived unit of force.
Oberkochen is a town (officially a city, despite its size) in the Ostalbkreis, in Baden-Württemberg, in Germany, central Europe.
The Observatory of Strasbourg is an astronomical observatory in Strasbourg, France.
The Oort constants (discovered by Jan Oort) A and B are empirically derived parameters that characterize the local rotational properties of our galaxy, the Milky Way, in the following manner: \begin & A.
The Oort limit is a theoretical location at the outer limits of the Oort cloud, where the amount of comets and minor planets orbiting the Sun drops drastically, or drops entirely.
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.
Post-Newtonian formalism is a calculational tool that expresses Einstein's (nonlinear) equations of gravity in terms of the lowest-order deviations from Newton's law of universal gravitation.
In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation.
Photomultiplier tubes (photomultipliers or PMTs for short), members of the class of vacuum tubes, and more specifically vacuum phototubes, are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum.
The Pleiades (also known as the Seven Sisters and Messier 45), are an open star cluster containing middle-aged, hot B-type stars located in the constellation of Taurus.
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.
A quasar (also known as a QSO or quasi-stellar object) is an extremely luminous active galactic nucleus (AGN).
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.
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.
Rheinmetall Air Defence AG is a division of German armament manufacturer Rheinmetall, created when the company's Oerlikon Contraves unit was renamed on 1 January 2009 and integrated with Rheinmetall's other air-defence products.
RR Lyrae variables are periodic variable stars, commonly found in globular clusters.
RUAG Space is the Space Division of the Swiss technology group RUAG.
The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz).
In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit.
A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations.
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other planets.
The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States.
A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects.
In physics, special relativity (SR, also known as the special theory of relativity or STR) is the generally accepted and experimentally well-confirmed physical theory regarding the relationship between space and time.
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
In everyday use and in kinematics, the speed of an object is the magnitude of its velocity (the rate of change of its position); it is thus a scalar quantity.
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.
Springer Science+Business Media or Springer, part of Springer Nature since 2015, is a global publishing company that publishes books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.
The standard error (SE) of a statistic (usually an estimate of a parameter) is the standard deviation of its sampling distribution or an estimate of that standard deviation.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
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 star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction.
A stellar association is a very loose star cluster, looser than both open clusters and globular clusters.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
Stellar evolution is the process by which a star changes over the course of time.
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.
Stars of different mass and age have varying internal structures.
A subdwarf, sometimes denoted by "sd", is a star with luminosity class VI under the Yerkes spectral classification system.
Thales Alenia Space is a Franco-Italian aerospace manufacturer formed after the Thales Group bought the participation of Alcatel in the two joint-ventures between Alcatel and Leonardo, Alcatel Alenia Space and Telespazio.
Trigonometry (from Greek trigōnon, "triangle" and metron, "measure") is a branch of mathematics that studies relationships involving lengths and angles of triangles.
The Tycho-2 Catalogue is an astronomical catalogue of more than 2.5 million of the brightest stars.
The UBV photometric system (Ultraviolet, Blue, Visual), also called the Johnson system (or Johnson-Morgan system), is a wide band photometric system for classifying stars according to their colors.
The United States Naval Observatory (USNO) is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation and Timing (PNT) for the United States Navy and the United States Department of Defense.
Vélizy-Villacoublay is a commune in the Yvelines department in the Île-de-France in north-central France.
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.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.
In photography and optics, vignetting (vignette) is a reduction of an image's brightness or saturation toward the periphery compared to the image center.
A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.
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.
Zürich or Zurich is the largest city in Switzerland and the capital of the canton of Zürich.
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.
3C 273 is a quasar located in the constellation Virgo.
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