169 relations: Accademia dei Lincei, Achromatic lens, Air mass (astronomy), Airborne observatory, Allen & Unwin, Altazimuth mount, Amateur astronomy, Amateur telescope making, Ancient Greek, Angular diameter, Angular resolution, Antenna (radio), Aperture masking interferometry, Aperture synthesis, Arecibo Observatory, ASCOM (standard), Astrograph, Astronomer, Astronomical seeing, Astronomy, Atmosphere of Earth, Bahtinov mask, Binoculars, Bioptics (device), Bonaventura Cavalieri, Brady Haran, Brightness, Camera lens, Carey mask, Chandra X-ray Observatory, Chromatic aberration, Coded aperture, Comet seeker, Cosmic ray, Cosmic-ray observatory, Degree (angle), Dew shield, Directional antenna, Dynameter, Earth, Einstein Observatory, Electromagnetic radiation, Electromagnetic spectrum, Ellipse, Encyclopedia of the History of Arabic Science, Energetic neutral atom, Equatorial mount, Extreme ultraviolet, Extremely high frequency, Extremely low frequency, ..., F-number, Far infrared, Far-infrared astronomy, Femto-, Fermi Gamma-ray Space Telescope, First light (astronomy), Focus (optics), Fresnel Imager, Galileo Galilei, Gamma ray, Gamma-ray astronomy, Giovanni Demisiani, Glass, GoTo (telescopes), Gravitational wave, Gravitational-wave astronomy, Gravitational-wave observatory, HALCA, Hans Lippershey, Hans Wolter, Hartmann mask, Heavy metals, High-energy astronomy, Hubble Space Telescope, Hyperbola, Ice, Image-forming optical system, Infrared, Infrared astronomy, Infrared telescope, Interstellar Boundary Explorer, Isaac Newton, Jacob Metius, James Clerk Maxwell Telescope, James Gregory (mathematician), Japan, Jay Pasachoff, Keyhole problem, Lens (optics), Light, List of largest optical reflecting telescopes, List of largest optical refracting telescopes, List of largest optical telescopes historically, List of optical telescopes, List of radio telescopes, List of solar telescopes, List of space telescopes, List of telescope parts and construction, List of telescope types, Marin Mersenne, McGraw-Hill Education, Micro-, Microscope, Microwave, Milli-, Mirror, MIT Press, Monocular, Netherlands, Neutrino, Neutrino astronomy, Neutrino detector, Newtonian telescope, Niccolò Zucchi, Objective (optics), Observation, Observatory, Optical instrument, Optical telescope, Parabola, Parabolic reflector, Patent, Photomultiplier, Quasar, Radar astronomy, Radio, Radio astronomy, Radio spectrum, Radio telescope, Reflecting telescope, Refracting telescope, Remote Telescope Markup Language, Robotic telescope, ROSAT, Routledge, Satellite, Search for extraterrestrial intelligence, Sidereus Nuncius, Solar and Heliospheric Observatory, Solar telescope, Space telescope, Speculum metal, Spherical aberration, Spitzer Space Telescope, Spotting scope, Submillimetre astronomy, Terahertz radiation, Theodolite, Timeline of telescope technology, Timeline of telescopes, observatories, and observing technology, TRACE, Ultraviolet, Ultraviolet astronomy, University of Nottingham, VERITAS, Very-long-baseline interferometry, Visible spectrum, Visible-light astronomy, Water, Wavelength, Wide Field Camera 3, Wolter telescope, X-ray, X-ray astronomy, X-ray optics, X-ray telescope, Zacharias Janssen, 17th century, 20th century. Expand index (119 more) » « Shrink index
The Accademia dei Lincei (literally the "Academy of the Lynx-Eyed", but anglicised as the Lincean Academy) is an Italian science academy, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy.
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration.
In astronomy, air mass (airmass, or AM) is the path length for light from a celestial source to pass through the atmosphere.
An airborne observatory is an airplane, airship, or balloon with an astronomical telescope.
Allen & Unwin is an Australian independent publishing company, established in Australia in 1976 as a subsidiary of the British firm George Allen & Unwin Ltd., which was founded by Sir Stanley Unwin in August 1914 and went on to become one of the leading publishers of the twentieth century.
An altazimuth or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two perpendicular axes – one vertical and the other horizontal.
Amateur astronomy is a hobby whose participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes.
Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional.
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.
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.
Angular resolution or spatial resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.
In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.
Aperture Masking Interferometry is a form of speckle interferometry, that allows diffraction limited imaging from ground-based telescopes, and is a planned high contrast imaging mode on the James Webb Space Telescope.
Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection.
The Arecibo Observatory is a radio telescope in the municipality of Arecibo, Puerto Rico.
ASCOM (an abbreviation for AStronomy Common Object Model) is an open initiative to provide a standard interface to a range of astronomy equipment including mounts, focusers and imaging devices in a Microsoft Windows environment.
An astrograph (astrographic camera) is a telescope designed for the sole purpose of astrophotography.
An astronomer is a scientist in the field of astronomy who concentrates their studies on a specific question or field outside the scope of Earth.
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.
Astronomy (from ἀστρονομία) is a natural science that studies celestial objects and phenomena.
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 Bahtinov mask is a device used to focus small astronomical telescopes accurately.
Binoculars or field glasses are two telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects.
Bioptics, also known as a bioptic in the singular, and sometimes more formally termed a bioptic telescope, is a term for a pair of vision-enhancement lenses.
Bonaventura Francesco Cavalieri (Cavalerius; 1598 – 30 November 1647) was an Italian mathematician and a Jesuate.
Brady John Haran (born 18 June 1976) is an Australian-born British independent filmmaker and video journalist who is known for his educational videos and documentary films produced for BBC News and his YouTube channels, the most notable being Periodic Videos and Numberphile.
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light.
A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.
A Carey mask (named after the inventor, George Carey) is a focusing aid for astronomical telescopes.
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999.
In optics, chromatic aberration (abbreviated CA; also called chromatic distortion and spherochromatism) is an effect resulting from dispersion in which there is a failure of a lens to focus all colors to the same convergence point.
Coded Apertures or Coded-Aperture Masks are grids, gratings, or other patterns of materials opaque to various wavelengths of electromagnetic radiation.
A comet seeker is a type of small telescope adapted especially to searching for comets: commonly of short focal length and large aperture, in order to secure the greatest brilliancy of light.
Cosmic rays are high-energy radiation, mainly originating outside the Solar System and even from distant galaxies.
A cosmic-ray observatory is a scientific installation built to detect high-energy-particles coming from space called cosmic rays.
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
A dew shield is a device used to prevent moisture or condensation buildup on the lens of a camera or telescope collector during night observations.
A directional antenna or beam antenna is an antenna which radiates or receives greater power in specific directions allowing increased performance and reduced interference from unwanted sources.
A dynameter is an instrument that measures the magnification of a telescope.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
Einstein Observatory (HEAO-2) was the first fully imaging X-ray telescope put into space and the second of NASA's three High Energy Astrophysical Observatories.
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.
The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.
In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve.
The Encyclopedia of the History of Arabic Science is a three-volume encyclopedia covering the history of Arabic contributions to science, mathematics and technology which had a marked influence on the Middle Ages in Europe.
Energetic neutral atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere, even to its outer boundary.
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis parallel to the Earth's axis of rotation.
Extreme ultraviolet radiation (EUV or XUV) or high-energy ultraviolet radiation is electromagnetic radiation in the part of the electromagnetic spectrum spanning wavelengths from 124 nm down to 10 nm, and therefore (by the Planck–Einstein equation) having photons with energies from 10 eV up to 124 eV (corresponding to 124 nm to 10 nm respectively).
Extremely high frequency (EHF) is the International Telecommunication Union (ITU) designation for the band of radio frequencies in the electromagnetic spectrum from 30 to 300 gigahertz (GHz).
Extremely low frequency (ELF) is the ITU designation for electromagnetic radiation (radio waves) with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively.
The f-number of an optical system (such as a camera lens) is the ratio of the system's focal length to the diameter of the entrance pupil.
Far infrared (FIR) is a region in the infrared spectrum of electromagnetic radiation.
Far-infrared astronomy is the branch of astronomy and astrophysics that deals with objects visible in far-infrared radiation (extending from 30 µm towards submillimeter wavelengths around 450 µm).
Femto- (symbol f) is a unit prefix in the metric system denoting a factor of 10−15 or.
The Fermi Gamma-ray Space Telescope (FGST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit.
In astronomy, first light is the first use of a telescope (or, in general, a new instrument) to take an astronomical image after it has been constructed.
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge.
--> A Fresnel imager is a proposed ultra-lightweight design for a space telescope that uses a Fresnel array as primary optics instead of a typical lens.
Galileo Galilei (15 February 1564Drake (1978, p. 1). The date of Galileo's birth is given according to the Julian calendar, which was then in force throughout Christendom. In 1582 it was replaced in Italy and several other Catholic countries with the Gregorian calendar. Unless otherwise indicated, dates in this article are given according to the Gregorian calendar. – 8 January 1642) was an Italian polymath.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
Gamma-ray astronomy is the astronomical observation of gamma rays,Astronomical literature generally hyphenates "gamma-ray" when used as an adjective, but uses "gamma ray" without a hyphen for the noun.
Giovanni Demisiani (Ἰωάννης Δημησιάνος; died 1614), a Greek from Zakynthos, was a theologian, chemist, mathematician to Cardinal Gonzaga, and member of the Accademia dei Lincei.
Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage in, for example, window panes, tableware, and optoelectronics.
In amateur astronomy, "GoTo" refers to a type of telescope mount and related software that can automatically point a telescope at astronomical objects that the user selects.
Gravitational waves are the disturbance in the fabric ("curvature") of spacetime generated by accelerated masses and propagate as waves outward from their source at the speed of light.
Gravitational-wave astronomy is an emerging branch of observational astronomy which aims to use gravitational waves (minute distortions of spacetime predicted by Einstein's theory of general relativity) to collect observational data about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
A gravitational-wave observatory (or gravitational-wave detector) is any device designed to measure gravitational waves, tiny distortions of spacetime that were first predicted by Einstein in 1916.
HALCA (Highly Advanced Laboratory for Communications and Astronomy), also known for its project name VSOP (VLBI Space Observatory Programme), or the code name MUSES-B (for the second of the Mu Space Engineering Spacecraft series), is a Japanese 8 meter diameter radio telescope satellite which was used for Very Long Baseline Interferometry (VLBI).
Hans Lippershey (1570 – buried 29 September 1619), also known as Johann Lippershey or Lipperhey, was a German-Dutch spectacle-maker.
Hans Wolter (11 May 1911 – 17 August 1978) was a German physicist who designed an aplanatic system of grazing incidence mirrors that satisfied the Abbe sine condition (i.e. free of both spherical aberration and coma).
Hartmann mask is a tool to help focusing telescopes, mainly used by amateur astronomers.
Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers.
High energy astronomy is the study of astronomical objects that release electromagnetic radiation of highly energetic wavelengths.
The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
In mathematics, a hyperbola (plural hyperbolas or hyperbolae) is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set.
Ice is water frozen into a solid state.
In optics, an image-forming optical system is a system capable of being used for imaging.
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.
Infrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared (IR) radiation.
An infrared telescope is a telescope that uses infrared light to detect celestial bodies.
Interstellar Boundary Explorer (IBEX) is a NASA satellite that is making a map of the boundary between the Solar System and interstellar space.
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, astronomer, theologian, author and physicist (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time, and a key figure in the scientific revolution.
Jacob (Jacobus; sometimes James) Metius (after 1571–1624/1631) was a Dutch instrument-maker and a specialist in grinding lenses.
The James Clerk Maxwell Telescope (JCMT) is a submillimetre-wavelength telescope at Mauna Kea Observatory in Hawaii.
James Gregory FRS (November 1638 – October 1675) was a Scottish mathematician and astronomer.
Japan (日本; Nippon or Nihon; formally 日本国 or Nihon-koku, lit. "State of Japan") is a sovereign island country in East Asia.
Jay Myron Pasachoff (born 1943) is an American astronomer.
The keyhole problem, in the context of astronomy, refers to the difficulty that azimuth-elevation type telescopes or antenna gimbal systems encounter in crossing the zenith.
A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
This list of the largest optical reflecting telescopes with objective diameters of or greater is sorted by aperture, which is one limit on the light-gathering power and resolution of a reflecting telescope's optical assembly.
Here is a list of the largest optical refracting telescopes sorted by lens diameter and focal length.
Telescope have grown in size since they first appeared around 1608.
* List of largest optical reflecting telescopes - List of large optical telescopes.
This is a list of radio telescopes - over one hundred - that are or have been used for radio astronomy.
List of solar telescopes sorted by default by year of completion, with newer telescopes higher up.
This list of space telescopes (astronomical space observatories) is grouped by major frequency ranges: gamma ray, x-ray, ultraviolet, visible, infrared, microwave and radio.
The following are lists of devices categorized as types of telescopes or devices associated with telescopes.
Marin Mersenne, Marin Mersennus or le Père Mersenne (8 September 1588 – 1 September 1648) was a French polymath, whose works touched a wide variety of fields.
McGraw-Hill Education (MHE) is a learning science company and one of the "big three" educational publishers that provides customized educational content, software, and services for pre-K through postgraduate education.
Micro- (symbol µ) is a unit prefix in the metric system denoting a factor of 10−6 (one millionth).
A microscope (from the μικρός, mikrós, "small" and σκοπεῖν, skopeîn, "to look" or "see") is an instrument used to see objects that are too small to be seen by the naked eye.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between and.
Milli- (symbol m) is a unit prefix in the metric system denoting a factor of one thousandth (10−3).
A mirror is an object that reflects light in such a way that, for incident light in some range of wavelengths, the reflected light preserves many or most of the detailed physical characteristics of the original light, called specular reflection.
The MIT Press is a university press affiliated with the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts (United States).
A monocular is a modified refracting telescope used to magnify the images of distant objects by passing light through a series of lenses and usually prisms, the application of prisms resulting in a lightweight, compact telescope.
The Netherlands (Nederland), often referred to as Holland, is a country located mostly in Western Europe with a population of seventeen million.
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.
Neutrino astronomy is the branch of astronomy that observes astronomical objects with neutrino detectors in special observatories.
A neutrino detector is a physics apparatus which is designed to study neutrinos.
The Newtonian telescope, also called the Newtonian reflector or just the Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton (1642–1727), using a concave primary mirror and a flat diagonal secondary mirror.
Niccolò Zucchi (December 6, 1586 – May 21, 1670) was an Italian Jesuit, astronomer, and physicist.
In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image.
Observation is the active acquisition of information from a primary source.
An observatory is a location used for observing terrestrial or celestial events.
An optical instrument either processes light waves to enhance an image for viewing, or analyzes light waves (or photons) to determine one of a number of characteristic properties.
An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors.
In mathematics, a parabola is a plane curve which is mirror-symmetrical and is approximately U-shaped.
A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves.
A patent is a set of exclusive rights granted by a sovereign state or intergovernmental organization to an inventor or assignee for a limited period of time in exchange for detailed public disclosure of an invention.
Photomultiplier tubes (photomultipliers or PMTs for short), members of the class of vacuum tubes, and more specifically vacuum phototubes, are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum.
A quasar (also known as a QSO or quasi-stellar object) is an extremely luminous active galactic nucleus (AGN).
Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the reflections.
Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width.
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies.
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3 000 GHz (3 THz).
A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy.
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image.
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope).
The Remote Telescope Markup Language (RTML) is an XML dialect for controlling remote and/or robotic telescopes.
A robotic telescope is an astronomical telescope and detector system that makes observations without the intervention of a human.
ROSAT (short for Röntgensatellit, in German X-rays are called Röntgenstrahlen, in honour of Wilhelm Röntgen) was a German Aerospace Center-led satellite X-ray telescope, with instruments built by West Germany, the United Kingdom and the United States.
Routledge is a British multinational publisher.
In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit.
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other planets.
Sidereus Nuncius (usually Sidereal Messenger, also Starry Messenger or Sidereal Message) is a short astronomical treatise (or pamphlet) published in New Latin by Galileo Galilei on March 13, 1610.
The Solar and Heliospheric Observatory (SOHO) is a spacecraft built by a European industrial consortium led by Matra Marconi Space (now Astrium) that was launched on a Lockheed Martin Atlas II AS launch vehicle on December 2, 1995, to study the Sun, and has discovered over 3000 comets.
A solar telescope is a special purpose telescope used to observe the Sun.
A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects.
Speculum metal is a mixture of around two-thirds copper and one-third tin making a white brittle alloy that can be polished to make a highly reflective surface.
Spherical aberration is an optical effect observed in an optical device (lens, mirror, etc.) that occurs due to the increased refraction of light rays when they strike a lens or a reflection of light rays when they strike a mirror near its edge, in comparison with those that strike close to the centre.
The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003 and still operating as of 2018.
A spotting scope is a small portable high-power telescope with added optics to present an erect image, optimized for the observation of terrestrial objects.
Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum.
Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahertz (THz; 1012 Hz).
A theodolite is a precision instrument for measuring angles in the horizontal and vertical planes.
The following timeline lists the significant events in the invention and development of the telescope.
Timeline of telescopes, observatories, and observing technology.
Transition Region and Coronal Explorer (TRACE) was a NASA heliophysics and solar observatory designed to investigate the connections between fine-scale magnetic fields and the associated plasma structures on the Sun by providing high resolution images and observation of the solar photosphere, the transition region, and the corona.
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.
Ultraviolet astronomy is the observation of electromagnetic radiation at ultraviolet wavelengths between approximately 10 and 320 nanometres; shorter wavelengths—higher energy photons—are studied by X-ray astronomy and gamma ray astronomy.
The University of Nottingham is a public research university in Nottingham, United Kingdom.
VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a major ground-based gamma-ray observatory with an array of four 12 meter optical reflectors for gamma-ray astronomy in the GeV – TeV photon energy range.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye.
Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes).
Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
The Wide Field Camera 3 (WFC3) is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum.
A Wolter telescope is a telescope for X-rays that only uses grazing incidence optics – mirrors that reflect X-rays at very shallow angles.
X-rays make up X-radiation, a form of electromagnetic radiation.
X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects.
X-ray optics is the branch of optics that manipulates X-rays instead of visible light.
An X-ray telescope (XRT) is a telescope that is designed to observe remote objects in the X-ray spectrum.
Zacharias Janssen (also Zacharias Jansen or Sacharias Jansen) (1585 – pre-1632) was a Dutch spectacle-maker from Middelburg associated with the invention of the first optical telescope.
The 17th century was the century that lasted from January 1, 1601, to December 31, 1700, in the Gregorian calendar.
The 20th century was a century that began on January 1, 1901 and ended on December 31, 2000.