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Proper motion

Index 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. [1]

81 relations: Aldebaran, Alpha Centauri, Andromeda Galaxy, Andromeda–Milky Way collision, Angle, Apparent magnitude, Apparent place, Arcturus, Astrometry, Axial precession, Barnard's Star, Bayer designation, Blink comparator, Celestial coordinate system, Celestial sphere, Center of mass, Constellation, Coordinate system, Crux, Declination, Delphinus, Dimension, Double star, Edmond Halley, Epoch (astronomy), Epsilon Indi, Equatorial coordinate system, Euclidean vector, Fixed stars, Galactic coordinate system, Galaxy rotation curve, Gliese 1, Glossary of astronomy, Groombridge 1830, Hipparchus, Hipparcos, Image differencing, Kapteyn's Star, Lacaille 9352, Lalande 21185, Leonard–Merritt mass estimator, Light-year, List of nearest stars and brown dwarfs, Local Group, Local standard of rest, Macrobius, Messier 106, Milky Way, Minute and second of arc, Motion (physics), ..., National Geographic Society – Palomar Observatory Sky Survey, Open cluster, Parsec, Peculiar velocity, Position angle, Pythagorean theorem, Radial velocity, Red dwarf, Relative velocity, Rho Aquilae, Right ascension, Sagittarius A*, Selection bias, SIMBAD, Sirius, Solar apex, Solar mass, Solar System, Star, Stellar kinematics, Sun, Teegarden's Star, Telescope, The Astrophysical Journal, Time, Triangulum Galaxy, Ursa Major, Very-long-baseline interferometry, Wolf 424, Year, 61 Cygni. Expand index (31 more) »


Aldebaran, designated Alpha Tauri (α Tauri, abbreviated Alpha Tau, α Tau), is an orange giant star located about 65 light-years from the Sun in the zodiac constellation of Taurus.

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Alpha Centauri

Alpha Centauri (α Centauri, abbreviated Alf Cen or α Cen) is the star system closest to the Solar System, being from the Sun.

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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.

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Andromeda–Milky Way collision

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.

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In plane geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle.

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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.

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Apparent place

The apparent place of an object is its position in space as seen by an observer.

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Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.

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Axial precession

In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis.

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Barnard's Star

Barnard's Star is a very-low-mass red dwarf about 6 light-years away from Earth in the constellation of Ophiuchus.

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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.

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Blink comparator

A blink comparator was a viewing apparatus used by astronomers to find differences between two photographs of the night sky.

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Celestial coordinate system

In astronomy, a celestial coordinate system is a system for specifying positions of celestial objects: satellites, planets, stars, galaxies, and so on.

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Celestial sphere

In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.

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Center of mass

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.

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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.

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Coordinate system

In geometry, a coordinate system is a system which uses one or more numbers, or coordinates, to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space.

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Crux is a constellation located in the southern sky in a bright portion of the Milky Way.

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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.

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Delphinus (Eng. U.S.) Eng.

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In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it.

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Double star

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.

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Edmond Halley

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

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Epoch (astronomy)

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.

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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.

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Equatorial coordinate system

The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects.

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Euclidean vector

In mathematics, physics, and engineering, a Euclidean vector (sometimes called a geometric or spatial vector, or—as here—simply a vector) is a geometric object that has magnitude (or length) and direction.

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Fixed stars

The fixed stars (stellae fixae) comprise the background of astronomical objects that appear to not move relative to each other in the night sky compared to the foreground of Solar System objects that do.

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Galactic coordinate system

The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way galaxy, and the fundamental plane parallel to an approximation of the galactic plane but offset to its north.

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Galaxy rotation curve

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.

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Gliese 1

Gliese 1 is a red dwarf in the constellation Sculptor, which is found in the southern celestial hemisphere.

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Glossary of astronomy

This page is a glossary of astronomy.

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Groombridge 1830

Groombridge 1830 (also known as 1830 Groombridge or Argelander's Star) is a star in the constellation Ursa Major.

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

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Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.

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Image differencing

Image differencing is an image processing technique used to determine changes between images.

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Kapteyn's Star

Kapteyn's Star is a class M1 red subdwarf about 12.76 light years from Earth in the southern constellation Pictor; it is the closest halo star to the Solar System.

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Lacaille 9352

Lacaille 9352 (Lac 9352) is a star in the southern constellation of Piscis Austrinus.

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Lalande 21185

Lalande 21185 is a star in the constellation of Ursa Major, relevant for being the brightest red dwarf observable in the northern hemisphere (only AX Microscopii and Lacaille 9352, in the southern hemisphere, are brighter).

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Leonard–Merritt mass estimator

The Leonard–Merritt mass estimator is a formula for estimating the mass of a spherical stellar system using the apparent (angular) positions and proper motions of its component stars.

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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.

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List of nearest stars and brown dwarfs

The following two lists include all the known stars and brown dwarfs that are within of the Sun, or were/will be within in the astronomically near past or future.

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Local Group

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

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Local standard of rest

In astronomy, the local standard of rest or LSR follows the mean motion of material in the Milky Way in the neighborhood of the Sun.

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Macrobius, fully Macrobius Ambrosius Theodosius, also known as Theodosius, was a Roman provincial who lived during the early fifth century, at the transition of the Roman to the Byzantine Empire, and when Latin was as widespread as Greek among the elite.

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Messier 106

Messier 106 (also known as NGC 4258) is an intermediate spiral galaxy in the constellation Canes Venatici.

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Milky Way

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

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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.

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Motion (physics)

In physics, motion is a change in position of an object over time.

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National Geographic Society – Palomar Observatory Sky Survey

The National Geographic Society – Palomar Observatory Sky Survey (NGS-POSS) was a major astronomical survey, that took almost 2,000 photographic plates of the night sky.

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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.

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The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.

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Peculiar velocity

Peculiar motion or peculiar velocity refers to the velocity of an object relative to a rest frame — usually a frame in which the average velocity of some objects is zero.

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Position angle

Position angle, usually abbreviated PA, is the convention for measuring angles on the sky in astronomy.

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Pythagorean theorem

In mathematics, the Pythagorean theorem, also known as Pythagoras' theorem, is a fundamental relation in Euclidean geometry among the three sides of a right triangle.

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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.

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Red dwarf

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

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Relative velocity

The relative velocity \vec_ (also \vec_ or \vec_) is the velocity of an object or observer B in the rest frame of another object or observer A.

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Rho Aquilae

Rho Aquilae, ρ Aquilae, is the Bayer designation for a star in the northern constellation of Delphinus.

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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.

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Sagittarius A*

Sagittarius A* (pronounced "Sagittarius A-star", standard abbreviation Sgr A*) is a bright and very compact astronomical radio source at the center of the Milky Way, near the border of the constellations Sagittarius and Scorpius.

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Selection bias

Selection bias is the bias introduced by the selection of individuals, groups or data for analysis in such a way that proper randomization is not achieved, thereby ensuring that the sample obtained is not representative of the population intended to be analyzed.

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SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data) is an astronomical database of objects beyond the Solar System.

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

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Solar apex

The solar apex, or the Apex of the Sun's Way, refers to the direction that the Sun travels with respect to the Local Standard of Rest.

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Solar mass

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

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Solar System

The Solar SystemCapitalization of the name varies.

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

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Stellar kinematics

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

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

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Teegarden's Star

Teegarden's Star (SO J025300.5+165258, 2MASS J02530084+1652532, LSPM J0253+1652) is an M-type red dwarf in the constellation Aries, about 12 light-years from the Solar System.

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

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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.

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Time is the indefinite continued progress of existence and events that occur in apparently irreversible succession from the past through the present to the future.

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Triangulum Galaxy

The Triangulum Galaxy is a spiral galaxy approximately 3 million light-years (ly) from Earth in the constellation Triangulum.

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Ursa Major

Ursa Major (also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory.

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Very-long-baseline interferometry

Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.

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Wolf 424

Wolf 424 is a binary star system comprising two red dwarf stars at a distance of approximately 14.2 light years from the Sun.

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A year is the orbital period of the Earth moving in its orbit around the Sun.

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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.

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Redirects here:

Common proper motion star, High proper motion star, Intrinsic motion, Proper Motion, Proper motion star, Proper motions, Proper-motion.


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

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