90 relations: AB magnitude, Absolute magnitude, Absorption (electromagnetic radiation), Angular diameter, Apparent magnitude, Astronomical object, Astronomical radio source, Astronomy, Astrophysical maser, Atmosphere of Earth, Australia Telescope National Facility, Bandwidth (signal processing), Beta Draconis, Betelgeuse, Black body, Bolometer, Bolometric correction, Cambridge University Press, Circumstellar dust, Deneb, Denebola, Earth, Effective temperature, Energy, Extinction (astronomy), Flux, Galaxy, HD 113766, HD 149382, HD 40307, Hertzsprung–Russell diagram, HIP 13044, Hipparchus, Institute for Advanced Study, International System of Units, Interstellar medium, Inverse-square law, Isotropy, Jansky, Joule, K band (infrared), K correction, Kelvin, Lambda Pegasi, List of brightest stars, List of most luminous stars, Logarithmic scale, Luminosity distance, Magnitude (astronomy), Main sequence, ..., Mass–luminosity relation, Milky Way, N. R. Pogson, Neutrino, O-type main-sequence star, Orders of magnitude (power), Parallax, Parsec, Passband, Photometric system, Photometry (astronomy), Pleione (star), Power (physics), R136a1, Radiant energy, Radius, Redshift, Rest frame, Solar luminosity, Spectral flux density, Spectral index, Sphere, Springer Science+Business Media, Star, Stefan–Boltzmann constant, Stefan–Boltzmann law, Stellar classification, Stellar parallax, Sun, Synonym, Telescope, Time, UBV photometric system, University of Chicago Press, Vega, Very-long-baseline interferometry, Watt, Wavelength, Wolf–Rayet star, 54 Piscium. Expand index (40 more) » « Shrink index
The AB magnitude system is an astronomical magnitude system.
Absolute magnitude is a measure of the luminosity of a celestial object, on a logarithmic astronomical magnitude scale.
In physics, absorption of electromagnetic radiation is the way in which the energy of a photon is taken up by matter, typically the electrons of an atom.
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 apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.
Astronomical radio sources are objects in outer space that emit strong radio waves.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
An astrophysical maser is a naturally occurring source of stimulated spectral line emission, typically in the microwave portion of the electromagnetic spectrum.
The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity.
The Commonwealth Scientific and Industrial Research Organisation (CSIRO)'s radio astronomy observatories are collectively known as the Australia Telescope National Facility (ATNF), with the facility supporting Australia's research in radio astronomy.
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.
Beta Draconis (β Draconis, abbreviated Beta Dra, β Dra) is a binary star and the third-brightest star in the northern circumpolar constellation of Draco.
Betelgeuse, also designated Alpha Orionis (α Orionis, abbreviated Alpha Ori, α Ori), is the ninth-brightest star in the night sky and second-brightest in the constellation of Orion.
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence.
A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance.
In astronomy, the bolometric correction is the correction made to the absolute magnitude of an object in order to convert its visible magnitude to its bolometric magnitude.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
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.
Circumstellar dust is cosmic dust around a star.
Deneb, also designated α Cygni (Latinised alpha Cygni, abbreviated Alpha Cyg, α Cyg), is the brightest star in the constellation of Cygnus.
Denebola, also designated Beta Leonis (β Leonis, abbreviated Beta Leo, β Leo) is the second-brightest star in the zodiac constellation of Leo, although the two components of the γ Leonis double star, which are unresolved to the naked eye, have a combined magnitude brighter than it.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
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.
In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.
In astronomy, extinction is the absorption and scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observer.
Flux describes the quantity which passes through a surface or substance.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.
HD 113766 is a binary star system located 424 light years from Earth in the direction of the constellation Centaurus.
HD 149382 is a star in the constellation of Ophiuchus with an apparent visual magnitude of 8.943.
HD 40307 is an orange (K-type) main-sequence star located approximately 42 light-years away in the constellation of Pictor (the Easel), taking its primary name from its Henry Draper Catalogue designation.
The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.
HIP 13044 is a red horizontal-branch star about 2,300 light years (700 pc) from Earth in the constellation Fornax.
Hipparchus of Nicaea (Ἵππαρχος, Hipparkhos) was a Greek astronomer, geographer, and mathematician.
The Institute for Advanced Study (IAS) in Princeton, New Jersey, in the United States, is an independent, postdoctoral research center for theoretical research and intellectual inquiry founded in 1930 by American educator Abraham Flexner, together with philanthropists Louis Bamberger and Caroline Bamberger Fuld.
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.
In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy.
The inverse-square law, in physics, is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity.
Isotropy is uniformity in all orientations; it is derived from the Greek isos (ἴσος, "equal") and tropos (τρόπος, "way").
The jansky (symbol Jy) is a non-SI unit of spectral flux density, or spectral irradiance, used especially in radio astronomy.
The joule (symbol: J) is a derived unit of energy in the International System of Units.
In infrared astronomy, the K band is an atmospheric transmission window centered on 2.2 μm (in the near-infrared 136 THz range).
K correction is a correction to an astronomical object's magnitude (or equivalently, its flux) that allows a measurement of a quantity of light from an object at a redshift z to be converted to an equivalent measurement in the rest frame of the object.
The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
Lambda Pegasi (λ Peg, λ Pegasi) is a fourth-magnitude star in the constellation Pegasus.
This is a list of the brightest naked eye stars to +2.50 magnitude, as determined by their maximum, total, or combined apparent visual magnitudes as seen from Earth.
Below is a list of stars arranged in order of decreasing luminosity (increasing bolometric magnitude).
A logarithmic scale is a nonlinear scale used when there is a large range of quantities.
Luminosity distance DL is defined in terms of the relationship between the absolute magnitude M and apparent magnitude m of an astronomical object.
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.
In astronomy, the main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness.
In astrophysics, the mass–luminosity relation is an equation giving the relationship between a star's mass and its luminosity, first noted by Jakob Karl Ernst Halm.
The Milky Way is the galaxy that contains our Solar System.
Norman Robert Pogson, CIE (23 March 1829 – 23 June 1891) was an English astronomer who worked in India at the Madras observatory.
A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.
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.
An O-type main-sequence star (O V) is a main-sequence (core hydrogen-burning) star of spectral type O and luminosity class V. These stars have between 15 and 90 times the mass of the Sun and surface temperatures between 30,000 and 50,000 K. They are between 40,000 and 1,000,000 times as luminous as the Sun.
This page lists examples of the power in watts produced by various sources of energy.
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.
The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System.
A passband is the range of frequencies or wavelengths that can pass through a filter.
In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation.
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation.
Pleione, designated 28 Tauri and BU Tauri (abbreviated 28 Tau or BU Tau), is a binary star and the seventh-brightest star in the Pleiades star cluster (Messier 45).
In physics, power is the rate of doing work, the amount of energy transferred per unit time.
RMC 136a1 (usually abbreviated to R136a1) is a Wolf–Rayet star located at the center of R136, the central condensation of stars of the large NGC 2070 open cluster in the Tarantula Nebula.
In physics, and in particular as measured by radiometry, radiant energy is the energy of electromagnetic and gravitational radiation.
In classical geometry, a radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.
In special relativity the rest frame of a particle is the coordinate system (frame of reference) in which the particle is at rest.
The solar luminosity,, is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun.
In spectroscopy, spectral flux density is the quantity that describes the rate at which energy is transferred by electromagnetic radiation through a real or virtual surface, per unit surface area and per unit wavelength.
In astronomy, the spectral index of a source is a measure of the dependence of radiative flux density (that is, radiative flux per unit of frequency) on frequency.
A sphere (from Greek σφαῖρα — sphaira, "globe, ball") is a perfectly round geometrical object in three-dimensional space that is the surface of a completely round ball (viz., analogous to the circular objects in two dimensions, where a "circle" circumscribes its "disk").
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.
The Stefan–Boltzmann constant (also Stefan's constant), a physical constant denoted by the Greek letter ''σ'' (sigma), is the constant of proportionality in the Stefan–Boltzmann law: "the total intensity radiated over all wavelengths increases as the temperature increases", of a black body which is proportional to the fourth power of the thermodynamic temperature.
The Stefan–Boltzmann law describes the power radiated from a black body in terms of its temperature.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects.
The Sun is the star at the center of the Solar System.
A synonym is a word or phrase that means exactly or nearly the same as another word or phrase in the same language.
A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light).
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.
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 University of Chicago Press is the largest and one of the oldest university presses in the United States.
Vega, also designated Alpha Lyrae (α Lyrae, abbreviated Alpha Lyr or α Lyr), is the brightest star in the constellation of Lyra, the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.
The watt (symbol: W) is a unit of power.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
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.
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.
54 Piscium is an orange dwarf star approximately 36 light-years away in the constellation of Pisces.