Get it on Google Play
New! Download Unionpedia on your Android™ device!
Faster access than browser!

Photometry (astronomy)

Index Photometry (astronomy)

Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation. [1]

56 relations: Accuracy and precision, Active galactic nucleus, Air mass (astronomy), Albedo, American Association of Variable Star Observers, Ancient Greek, Aperture Photometry Tool, Apparent magnitude, Astronomical object, Astronomical seeing, Astronomical Society of the Pacific, Astronomy, Bidirectional reflectance distribution function, Binary star, Charge-coupled device, Distance, Electromagnetic radiation, Flux, Galaxy, Globular cluster, Hapke parameters, Hertzsprung–Russell diagram, Infrared, Instrumental magnitude, Inverse-square law, Light curve, Luminosity, Magnitude (astronomy), Measurement, Methods of detecting exoplanets, Minor planet, Minute and second of arc, Orbital period, Oxford University Press, Passband, Photometric system, Photometric-standard star, Pixel, Point source, Point spread function, Publications of the Astronomical Society of the Pacific, Radiation, Radiometry, Radius, Redshift survey, Rotation period, Solid angle, Spectrophotometry, Spectroscopy, Supernova, ..., Surface brightness, Telescope, Temperature, Ultraviolet, Variable star, Wavelength. Expand index (6 more) »

Accuracy and precision

Precision is a description of random errors, a measure of statistical variability.

New!!: Photometry (astronomy) and Accuracy and precision · See more »

Active galactic nucleus

An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion—and possibly all—of the electromagnetic spectrum, with characteristics indicating that the excess luminosity is not produced by stars.

New!!: Photometry (astronomy) and Active galactic nucleus · See more »

Air mass (astronomy)

In astronomy, air mass (airmass, or AM) is the path length for light from a celestial source to pass through the atmosphere.

New!!: Photometry (astronomy) and Air mass (astronomy) · See more »


Albedo (albedo, meaning "whiteness") is the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body (e.g. a planet like Earth).

New!!: Photometry (astronomy) and Albedo · See more »

American Association of Variable Star Observers

Since its founding in 1911, the American Association of Variable Star Observers (AAVSO) has coordinated, collected, evaluated, analyzed, published, and archived variable star observations made largely by amateur astronomers and makes the records available to professional astronomers, researchers, and educators.

New!!: Photometry (astronomy) and American Association of Variable Star Observers · See more »

Ancient Greek

The Ancient Greek language includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD.

New!!: Photometry (astronomy) and Ancient Greek · See more »

Aperture Photometry Tool

Aperture Photometry Tool (APT) is software with a graphical user interface for computing aperture photometry on astronomical imagery, which is a common research task in astronomy.

New!!: Photometry (astronomy) and Aperture Photometry Tool · See more »

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.

New!!: Photometry (astronomy) and Apparent magnitude · See more »

Astronomical object

An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.

New!!: Photometry (astronomy) and Astronomical object · See more »

Astronomical seeing

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.

New!!: Photometry (astronomy) and Astronomical seeing · See more »

Astronomical Society of the Pacific

The Astronomical Society of the Pacific (ASP) is an American scientific and educational organization, founded in San Francisco on February 7, 1889.

New!!: Photometry (astronomy) and Astronomical Society of the Pacific · See more »


Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.

New!!: Photometry (astronomy) and Astronomy · See more »

Bidirectional reflectance distribution function

The bidirectional reflectance distribution function (BRDF; f_(\omega_,\, \omega_)) is a function of four real variables that defines how light is reflected at an opaque surface.

New!!: Photometry (astronomy) and Bidirectional reflectance distribution function · See more »

Binary star

A binary star is a star system consisting of two stars orbiting around their common barycenter.

New!!: Photometry (astronomy) and Binary star · See more »

Charge-coupled device

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.

New!!: Photometry (astronomy) and Charge-coupled device · See more »


Distance is a numerical measurement of how far apart objects are.

New!!: Photometry (astronomy) and Distance · See more »

Electromagnetic radiation

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.

New!!: Photometry (astronomy) and Electromagnetic radiation · See more »


Flux describes the quantity which passes through a surface or substance.

New!!: Photometry (astronomy) and Flux · See more »


A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.

New!!: Photometry (astronomy) and Galaxy · See more »

Globular cluster

A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite.

New!!: Photometry (astronomy) and Globular cluster · See more »

Hapke parameters

The Hapke parameters are a set of parameters for an empirical model that is commonly used to describe the directional reflectance properties of the airless regolith surfaces of bodies in the solar system.

New!!: Photometry (astronomy) and Hapke parameters · See more »

Hertzsprung–Russell diagram

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.

New!!: Photometry (astronomy) and Hertzsprung–Russell diagram · See more »


Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.

New!!: Photometry (astronomy) and Infrared · See more »

Instrumental magnitude

Instrumental magnitude refers to an uncalibrated apparent magnitude, and, like its counterpart, it refers to the brightness of an astronomical object seen from an observer on Earth, but unlike its counterpart, it is only useful in relative comparisons to other astronomical objects in the same image (assuming the photometric calibration does not spatially vary across the image; in the case of images from the Palomar Transient Factory, the absolute photometric calibration involves a zero point that varies over the image by up to 0.16 magnitudes to make a required illumination correction).

New!!: Photometry (astronomy) and Instrumental magnitude · See more »

Inverse-square law

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.

New!!: Photometry (astronomy) and Inverse-square law · See more »

Light curve

In astronomy, a light curve is a graph of light intensity of a celestial object or region, as a function of time.

New!!: Photometry (astronomy) and Light curve · See more »


In astronomy, luminosity is the total amount of energy emitted per unit of time by a star, galaxy, or other astronomical object.

New!!: Photometry (astronomy) and Luminosity · See more »

Magnitude (astronomy)

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.

New!!: Photometry (astronomy) and Magnitude (astronomy) · See more »


Measurement is the assignment of a number to a characteristic of an object or event, which can be compared with other objects or events.

New!!: Photometry (astronomy) and Measurement · See more »

Methods of detecting exoplanets

Any planet is an extremely faint light source compared to its parent star.

New!!: Photometry (astronomy) and Methods of detecting exoplanets · See more »

Minor planet

A minor planet is an astronomical object in direct orbit around the Sun (or more broadly, any star with a planetary system) that is neither a planet nor exclusively classified as a comet.

New!!: Photometry (astronomy) and Minor planet · See more »

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.

New!!: Photometry (astronomy) and Minute and second of arc · See more »

Orbital period

The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.

New!!: Photometry (astronomy) and Orbital period · See more »

Oxford University Press

Oxford University Press (OUP) is the largest university press in the world, and the second oldest after Cambridge University Press.

New!!: Photometry (astronomy) and Oxford University Press · See more »


A passband is the range of frequencies or wavelengths that can pass through a filter.

New!!: Photometry (astronomy) and Passband · See more »

Photometric system

In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation.

New!!: Photometry (astronomy) and Photometric system · See more »

Photometric-standard star

Photometric-standard stars are a series of stars that have had their light output in various passbands of photometric system measured very carefully.

New!!: Photometry (astronomy) and Photometric-standard star · See more »


In digital imaging, a pixel, pel, dots, or picture element is a physical point in a raster image, or the smallest addressable element in an all points addressable display device; so it is the smallest controllable element of a picture represented on the screen.

New!!: Photometry (astronomy) and Pixel · See more »

Point source

A point source is a single identifiable localised source of something.

New!!: Photometry (astronomy) and Point source · See more »

Point spread function

The point spread function (PSF) describes the response of an imaging system to a point source or point object.

New!!: Photometry (astronomy) and Point spread function · See more »

Publications of the Astronomical Society of the Pacific

Publications of the Astronomical Society of the Pacific (often abbreviated as PASP in references and literature) is a monthly peer-reviewed scientific journal managed by the Astronomical Society of the Pacific.

New!!: Photometry (astronomy) and Publications of the Astronomical Society of the Pacific · See more »


In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

New!!: Photometry (astronomy) and Radiation · See more »


Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light.

New!!: Photometry (astronomy) and Radiometry · See more »


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.

New!!: Photometry (astronomy) and Radius · See more »

Redshift survey

In astronomy, a redshift survey is a survey of a section of the sky to measure the redshift of astronomical objects: usually galaxies, but sometimes other objects such as galaxy clusters or quasars.

New!!: Photometry (astronomy) and Redshift survey · See more »

Rotation period

In astronomy, the rotation period of a celestial object is the time that it takes to complete one revolution around its axis of rotation relative to the background stars.

New!!: Photometry (astronomy) and Rotation period · See more »

Solid angle

In geometry, a solid angle (symbol) is a measure of the amount of the field of view from some particular point that a given object covers.

New!!: Photometry (astronomy) and Solid angle · See more »


In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.

New!!: Photometry (astronomy) and Spectrophotometry · See more »


Spectroscopy is the study of the interaction between matter and electromagnetic radiation.

New!!: Photometry (astronomy) and Spectroscopy · See more »


A supernova (plural: supernovae or supernovas, abbreviations: SN and SNe) is a transient astronomical event that occurs during the last stellar evolutionary stages of a star's life, either a massive star or a white dwarf, whose destruction is marked by one final, titanic explosion.

New!!: Photometry (astronomy) and Supernova · See more »

Surface brightness

In astronomy, surface brightness quantifies the apparent brightness or flux density per unit angular area of a spatially extended object such as a galaxy or nebula, or of the night sky background.

New!!: Photometry (astronomy) and Surface brightness · See more »


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

New!!: Photometry (astronomy) and Telescope · See more »


Temperature is a physical quantity expressing hot and cold.

New!!: Photometry (astronomy) and Temperature · See more »


Ultraviolet (UV) is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.

New!!: Photometry (astronomy) and Ultraviolet · See more »

Variable star

A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates.

New!!: Photometry (astronomy) and Variable star · See more »


In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.

New!!: Photometry (astronomy) and Wavelength · See more »

Redirects here:

Brighter-fatter effect, Photoelectric magnitude, Photometric astrometry.


[1] https://en.wikipedia.org/wiki/Photometry_(astronomy)

Hey! We are on Facebook now! »