87 relations: Al-Ma'mun, Almanac, Analytical dynamics, Astronomical Almanac, Astronomical nutation, Astronomy, Astronomy & Astrophysics, Axial precession, Axis–angle representation, Bernhard Walther, Celestial equator, Celestial sphere, Century, Circumstellar habitable zone, Climate change, Declination, Denmark, Earth, Ecliptic, Epoch (astronomy), Epsilon, Equator, Exoplanet, Fundamental ephemeris, Georg von Peuerbach, Girolamo Fracastoro, Greek alphabet, Hemispheres of Earth, Ibn al-Shatir, Icarus (journal), International Astronomical Union, Invariable plane, J. B. Lippincott & Co., Jet Propulsion Laboratory Development Ephemeris, Julian day, Julian year (astronomy), Jupiter, Kepler (spacecraft), Macmillan Publishers, Mantle (geology), Mars, Mercury (planet), Middle Ages, Milankovitch cycles, Minute and second of arc, Moon, NASA, Nature (journal), Neptune, Newcomb's Tables of the Sun, ..., Northern Hemisphere, Numerical analysis, Observational astronomy, Office of Public Sector Information, Orbit, Orbit of the Moon, Orbital inclination, Orbital resonance, Perturbation (astronomy), Planet, Planetary core, Pluto, Polar motion, Pytheas, Regiomontanus, Right ascension, Right-hand rule, Rossiter–McLaughlin effect, Rotation around a fixed axis, Saturn, Science (journal), Season, Sharaf al-Dīn al-Ṭūsī, Solar System, Stability of the Solar System, Star, Summer, Sun, Term (logic), Terrestrial Time, Tidal acceleration, Tropical year, True polar wander, Tycho Brahe, Ulugh Beg, Uranus, Venus. Expand index (37 more) » « Shrink index
Abu al-Abbas al-Maʾmūn ibn Hārūn al-Rashīd (أبو العباس المأمون; September 786 – 9 August 833) was the seventh Abbasid caliph, who reigned from 813 until his death in 833.
An almanac (also spelled almanack and almanach) is an annual publication listing a set of events forthcoming in the next year.
In classical mechanics, analytical dynamics, or more briefly dynamics, is concerned with the relationship between motion of bodies and its causes, namely the forces acting on the bodies and the properties of the bodies, particularly mass and moment of inertia.
The Astronomical AlmanacThe Astronomical Almanac for the Year 2015, (United States Naval Observatory/Nautical Almanac Office, 2014).
Astronomical nutation is a phenomenon which causes the orientation of the axis of rotation of a spinning astronomical object to vary over time.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
Astronomy & Astrophysics is a peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics.
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis.
In mathematics, the axis–angle representation of a rotation parameterizes a rotation in a three-dimensional Euclidean space by two quantities: a unit vector indicating the direction of an axis of rotation, and an angle describing the magnitude of the rotation about the axis.
Bernhard Walther (1430June 19, 1504) was a German merchant, humanist and astronomer based in Nuremberg, Germany.
The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth.
In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.
A century (from the Latin centum, meaning one hundred; abbreviated c.) is a period of 100 years.
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years).
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.
Denmark (Danmark), officially the Kingdom of Denmark,Kongeriget Danmark,.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
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.
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.
Epsilon (uppercase Ε, lowercase ε or lunate ϵ; έψιλον) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid<!-- not close-mid, see Arvanti (1999) - Illustrations of the IPA: Modern Greek. --> front unrounded vowel.
An equator of a rotating spheroid (such as a planet) is its zeroth circle of latitude (parallel).
An exoplanet or extrasolar planet is a planet outside our solar system.
A fundamental ephemeris of the Solar System is a model of the objects of the system in space, with all of their positions and motions accurately represented.
Georg von Peuerbach (also Purbach, Peurbach, Purbachius; born May 30, 1423 – April 8, 1461) was an Austrian astronomer, mathematician and instrument maker, best known for his streamlined presentation of Ptolemaic astronomy in the Theoricae Novae Planetarum.
Girolamo Fracastoro (Hieronymus Fracastorius; c. 1476/86 August 1553) was an Italian physician, poet, and scholar in mathematics, geography and astronomy.
The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BC.
In geography and cartography, the hemispheres of Earth refer to any division of the globe into two hemispheres (from Ancient Greek ἡμισφαίριον hēmisphairion, meaning "half of a sphere").
ʿAlāʾ al‐Dīn ʿAlī ibn Ibrāhīm known as Ibn al-Shatir or Ibn ash-Shatir (ابن الشاطر; 1304–1375) was an Arab astronomer, mathematician and engineer.
Icarus is a scientific journal dedicated to the field of planetary science.
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.
The invariable plane of a planetary system, also called Laplace's invariable plane, is the plane passing through its barycenter (center of mass) perpendicular to its angular momentum vector.
The name Jet Propulsion Laboratory Development Ephemeris (followed by a number), the abbreviation JPL DE(number), or just DE(number) designates one of a series of models of the Solar System produced at the Jet Propulsion Laboratory in Pasadena, California, primarily for purposes of spacecraft navigation and astronomy.
Julian day is the continuous count of days since the beginning of the Julian Period and is used primarily by astronomers.
In astronomy, a Julian year (symbol: a) is a unit of measurement of time defined as exactly 365.25 days of SI seconds each.
Jupiter is the fifth planet from the Sun and the largest in the Solar System.
Kepler is a space observatory launched by NASA to discover Earth-size planets orbiting other stars.
Macmillan Publishers Ltd (occasionally known as the Macmillan Group) is an international publishing company owned by Holtzbrinck Publishing Group.
The mantle is a layer inside a terrestrial planet and some other rocky planetary bodies.
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
Mercury is the smallest and innermost planet in the Solar System.
In the history of Europe, the Middle Ages (or Medieval Period) lasted from the 5th to the 15th century.
Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.
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.
Neptune is the eighth and farthest known planet from the Sun in the Solar System.
Newcomb's Tables of the Sun is the short title and running head of a work by the American astronomer and mathematician Simon Newcomb entitled "Tables of the Motion of the Earth on its Axis and Around the Sun" on pages 1–169 of "Tables of the Four Inner Planets" (1895), volume VI of the serial publication Astronomical Papers Prepared for the Use of the American Ephemeris and Nautical Almanac.
The Northern Hemisphere is the half of Earth that is north of the Equator.
Numerical analysis is the study of algorithms that use numerical approximation (as opposed to general symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics).
Observational astronomy is a division of astronomy that is concerned with recording data about the observable universe, in contrast with theoretical astronomy, which is mainly concerned with calculating the measurable implications of physical models.
The Office of Public Sector Information (OPSI) is the body responsible for the operation of Her Majesty's Stationery Office (HMSO) and of other public information services of the United Kingdom.
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.
The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in about 27.322 days (a sidereal month) and one revolution relative to the Sun in about 29.530 days (a synodic month).
Orbital inclination measures the tilt of an object's orbit around a celestial body.
In celestial mechanics, an orbital resonance occurs when orbiting bodies exert a regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers.
In astronomy, perturbation is the complex motion of a massive body subject to forces other than the gravitational attraction of a single other massive body.
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.
The planetary core consists of the innermost layer(s) of a planet; which may be composed of solid and liquid layers.
Pluto (minor planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune.
Polar motion of the Earth is the motion of the Earth's rotational axis relative to its crust.
Pytheas of Massalia (Ancient Greek: Πυθέας ὁ Μασσαλιώτης Pythéas ho Massaliōtēs; Latin: Pytheas Massiliensis; fl. 4th century BC), was a Greek geographer and explorer from the Greek colony of Massalia (modern-day Marseille).
Johannes Müller von Königsberg (6 June 1436 – 6 July 1476), better known as Regiomontanus, was a mathematician and astronomer of the German Renaissance, active in Vienna, Buda and Nuremberg.
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.
In mathematics and physics, the right-hand rule is a common mnemonic for understanding orientation conventions for the vector cross product in three dimensions.
The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's secondary star or an extrasolar planet is seen to transit across the face of the primary or parent star.
Rotation around a fixed axis or about a fixed axis of revolution or motion with respect to a fixed axis of rotation is a special case of rotational motion.
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.
Science, also widely referred to as Science Magazine, is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals.
A season is a division of the year marked by changes in weather, ecology, and amount of daylight.
(c. 1135 – c. 1213) was an Iranian mathematician and astronomer of the Islamic Golden Age (during the Middle Ages).
The Solar SystemCapitalization of the name varies.
The stability of the Solar System is a subject of much inquiry in astronomy.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
Summer is the hottest of the four temperate seasons, falling after spring and before autumn.
The Sun is the star at the center of the Solar System.
In analogy to natural language, where a noun phrase refers to an object and a whole sentence refers to a fact, in mathematical logic, a term denotes a mathematical object and a formula denotes a mathematical fact.
Terrestrial Time (TT) is a modern astronomical time standard defined by the International Astronomical Union, primarily for time-measurements of astronomical observations made from the surface of Earth.
Tidal acceleration is an effect of the tidal forces between an orbiting natural satellite (e.g. the Moon), and the primary planet that it orbits (e.g. Earth).
A tropical year (also known as a solar year) is the time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice.
True polar wander is a solid-body rotation of a planet or moon with respect to its spin axis, causing the geographic locations of the north and south poles to change, or "wander".
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.
Mīrzā Muhammad Tāraghay bin Shāhrukh (میرزا محمد طارق بن شاہ رخ, میرزا محمد تراغای بن شاہ رخ), better known as Ulugh Beg (March 22, 1394 in Sultaniyeh, Persia – October 27, 1449, Samarkand), was a Timurid ruler as well as an astronomer, mathematician and sultan.
Uranus is the seventh planet from the Sun.
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.
Angled rotation of the Earth, Axial Tilt, Axial Tilts of Planets, Axial inclination, Axial inclinations, Axial incline, Axial inclines, Axial tilting, Axial tilts, Axis tilt, Earth axis, Earth's Axis, Earth's axial tilt, Earth's axis, Earth's inclination, Earths axis, Equatorial inclination to orbit, Mars's spin axis, Obliquities, Obliquitous, Obliquity, Obliquity of the ecliptic, Tilted axis.