74 relations: American Book Company (1890), Angular diameter, Angular momentum, Angular velocity, Apsidal precession, Apsis, Axial precession, Cambridge University Press, Celestial sphere, Chinese calendar, Circular orbit, Common law, Computus, Conjunction (astronomy), CRC Handbook of Chemistry and Physics, Day, Dragon, Earth's orbit, Eclipse, Eclipse cycle, Ecliptic, Ecliptic coordinate system, Egyptian calendar, Elliptic orbit, Ephemeris time, Epoch (astronomy), Equinox, Europe, Fixed stars, Full moon, Hebrew calendar, Hindu calendar, International Celestial Reference Frame, International System of Units, Interpretation Act 1978, Islamic calendar, ΔT, Julian year (astronomy), Law of Property Act 1925, Lunar calendar, Lunar mansion, Lunar node, Lunar phase, Middle East, Month, NASA, New moon, Nodal precession, Northern celestial hemisphere, Orbit of the Moon, ..., Orbital inclination, Orbital node, Orbital speed, Perturbation (astronomy), Position of the Sun, Precession, Retrograde and prograde motion, Saros (astronomy), Second, Secular variation, Shona people, Southern celestial hemisphere, Springer Science+Business Media, Star, Supermoon, Syzygy (astronomy), Terrestrial Time, Tibetan calendar, Tithi, Torque, Tropical year, Universal Time, Universe Today, Year. Expand index (24 more) » « Shrink index
The American Book Company (ABC) was an educational book publisher in the United States that specialized in elementary school, secondary school and collegiate-level textbooks.
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.
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum.
In physics, the angular velocity of a particle is the rate at which it rotates around a chosen center point: that is, the time rate of change of its angular displacement relative to the origin.
In celestial mechanics, apsidal precession or orbital precession is the precession (rotation) of the orbit of a celestial body.
An apsis (ἁψίς; plural apsides, Greek: ἁψῖδες) is an extreme point in the orbit of an object.
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.
The traditional Chinese calendar (official Chinese name: Rural Calendar, alternately Former Calendar, Traditional Calendar, or Lunar Calendar) is a lunisolar calendar which reckons years, months and days according to astronomical phenomena.
A circular orbit is the orbit with a fixed distance around the barycenter, that is, in the shape of a circle.
Common law (also known as judicial precedent or judge-made law, or case law) is that body of law derived from judicial decisions of courts and similar tribunals.
Computus (Latin for "computation") is a calculation that determines the calendar date of Easter.
In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth.
The CRC Handbook of Chemistry and Physics is a comprehensive one-volume reference resource for science research, currently in its 98th edition (with 2560 pages, June 23, 2017, Editor-in-Chief John R. Rumble).
A day, a unit of time, is approximately the period of time during which the Earth completes one rotation with respect to the Sun (solar day).
A dragon is a large, serpent-like legendary creature that appears in the folklore of many cultures around the world.
Earth's orbit is the trajectory along which Earth travels around the Sun.
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer.
Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles.
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 ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions and orbits of Solar System objects.
The ancient Egyptian calendar was a solar calendar with a 365-day year.
In astrodynamics or celestial mechanics, an elliptic orbit or elliptical orbit is a Kepler orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0.
The term ephemeris time (often abbreviated ET) can in principle refer to time in connection with any astronomical ephemeris.
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.
An equinox is commonly regarded as the moment the plane (extended indefinitely in all directions) of Earth's equator passes through the center of the Sun, which occurs twice each year, around 20 March and 22-23 September.
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere.
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.
The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective.
The Hebrew or Jewish calendar (Ha-Luah ha-Ivri) is a lunisolar calendar used today predominantly for Jewish religious observances.
Hindu calendar is a collective term for the various lunisolar calendars traditionally used in India.
In astrometry, an International Celestial Reference Frame (ICRF) is a realization of the International Celestial Reference System (ICRS) using reference celestial sources observed at radio wavelengths.
The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.
The Interpretation Act 1978 is an Act of the Parliament of the United Kingdom.
The Islamic, Muslim, or Hijri calendar (التقويم الهجري at-taqwīm al-hijrī) is a lunar calendar consisting of 12 months in a year of 354 or 355 days.
In precise timekeeping, ΔT (Delta T, delta-T, deltaT, or DT) is the time difference obtained by subtracting Universal Time (UT) from Terrestrial Time (TT):.
In astronomy, a Julian year (symbol: a) is a unit of measurement of time defined as exactly 365.25 days of SI seconds each.
The Law of Property Act 1925 is a statute of the United Kingdom Parliament.
A lunar calendar is a calendar based upon the monthly cycles of the Moon's phases (synodic months), in contrast to solar calendars, whose annual cycles are based only directly upon the solar year.
A lunar mansion is a segment of the ecliptic (often called a station or house) through which the Moon passes in its orbit around Earth, often used by ancient cultures as part of their calendar system. In general, though not always, the zodiac is divided into 27 or 28 segments relative to the fixed stars – one for each day of the lunar month.
The lunar nodes are the orbital nodes of the Moon, that is, the two points at which the orbit of the Moon crosses the ecliptic.
The lunar phase or phase of the Moon is the shape of the directly sunlit portion of the Moon as viewed from Earth.
The Middle Easttranslit-std; translit; Orta Şərq; Central Kurdish: ڕۆژھەڵاتی ناوین, Rojhelatî Nawîn; Moyen-Orient; translit; translit; translit; Rojhilata Navîn; translit; Bariga Dhexe; Orta Doğu; translit is a transcontinental region centered on Western Asia, Turkey (both Asian and European), and Egypt (which is mostly in North Africa).
A month is a unit of time, used with calendars, which is approximately as long as a natural period related to the motion of the Moon; month and Moon are cognates.
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.
In astronomy, the new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude.
Nodal precession is the precession of the orbital plane of a satellite around the rotation axis of an astronomical body such as Earth.
The Northern Celestial Hemisphere, or the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator.
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.
An orbital node is either of the two points where an orbit intersects a plane of reference to which it is inclined.
In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter or, if the object is much less massive than the largest body in the system, its speed relative to that largest body.
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.
The position of the Sun in the sky is a function of both the time and the geographic location of observation on Earth's surface.
Precession is a change in the orientation of the rotational axis of a rotating body.
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is the central object (right figure).
The Saros is a period of approximately 223 synodic months (approximately 6585.3211 days, or 18 years, 11 days, 8 hours), that can be used to predict eclipses of the Sun and Moon.
The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each.
The secular variation of a time series is its long-term non-periodic variation (see Decomposition of time series).
The Shona are a group of Bantu ethnic group native to Zimbabwe and neighbouring countries.
The Southern Celestial Hemisphere, or the Southern Sky, is the southern half of the celestial sphere, which appears to rotate around a polar axis due to Earth's rotation.
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.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
A supermoon is a full moon or a new moon that approximately coincides with the closest distance that the Moon reaches to Earth in its elliptic orbit, resulting in a slightly larger-than-usual apparent size of the lunar disk as seen from Earth.
In astronomy, a syzygy (from the Ancient Greek σύζυγος suzugos meaning, "yoked together") is a (usually) straight-line configuration of three or more celestial bodies in a gravitational system.
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.
The Tibetan calendar is a lunisolar calendar, that is, the Tibetan year is composed of either 12 or 13 lunar months, each beginning and ending with a new moon.
In Vedic timekeeping, a tithi (also spelled thithi) is a lunar day, or the time it takes for the longitudinal angle between the Moon and the Sun to increase by 12°.
Torque, moment, or moment of force is rotational force.
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.
Universal Time (UT) is a time standard based on Earth's rotation.
Universe Today (UT) is a popular North American-based non-commercial space and astronomy news website.
A year is the orbital period of the Earth moving in its orbit around the Sun.