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Spectrohelioscope
A spectrohelioscope is a type of solar telescope designed by George Ellery Hale in 1924 to allow the Sun to be viewed in a selected wavelength of light. The name comes from Latin- and Greek-based words: "Spectro," referring to the optical spectrum, "helio," referring to the Sun, and "scope," as in telescope. The basic spectrohelioscope is a complex machine that uses a spectroscope to scan the surface of the Sun. The image from the objective lens is focused on a narrow slit revealing only a thin portion of the Sun's surface. The light is then passed through a prism or diffraction grating In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structur ... to spread the light into a spectrum. The spectrum is then focused on another slit that allows only a narrow part of the spectrum (the desired wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrohelioscope
A spectrohelioscope is a type of solar telescope designed by George Ellery Hale in 1924 to allow the Sun to be viewed in a selected wavelength of light. The name comes from Latin- and Greek-based words: "Spectro," referring to the optical spectrum, "helio," referring to the Sun, and "scope," as in telescope. The basic spectrohelioscope is a complex machine that uses a spectroscope to scan the surface of the Sun. The image from the objective lens is focused on a narrow slit revealing only a thin portion of the Sun's surface. The light is then passed through a prism or diffraction grating In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structur ... to spread the light into a spectrum. The spectrum is then focused on another slit that allows only a narrow part of the spectrum (the desired wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum. Obsolete names for Sun telescopes include heliograph and photoheliograph. Professional solar telescopes Solar telescopes need optics large enough to achieve the best possible diffraction limit but less so for the associated light-collecting power of other astronomical telescopes. However, recently newer narrower filters and higher framerates have also driven solar telescopes towards photon-starved operations. Both the Daniel K. Inouye Solar Telescope as well as the proposed European Solar Telescope (EST) have larger apertures not only to increase the resolution, but also to increase the light-collecting power. Because solar telescopes operate during the day, seeing is generally worse than for night-time telescopes, because the ground around the telescope is heated which causes turbulence and degrades the res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Ellery Hale
George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading telescopes; namely, the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory, 100-inch Hooker reflecting telescope at Mount Wilson, and the 200-inch Hale reflecting telescope at Palomar Observatory. He also played a key role in the foundation of the International Union for Cooperation in Solar Research and the National Research Council, and in developing the California Institute of Technology into a leading research university. Early life and education George Ellery Hale was born on June 29, 1868, in Chicago, Illinois, to William Ellery Hale and Mary Browne.Adams 1939, p. 181. He is descended from Thomas Hale of Watton-on-Stone, Hertfordshire, England, whose son emigrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter ''lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' or simply light. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well. The spectrum does not contain all the colors that the human visual system can distinguish. '' Unsaturated colors'' such as pink, or purple variations like magenta, for example, are absen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscope
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light or a unit directly proportional to the photon energy, such as reciprocal centimeters or electron volts, which has a reciprocal relationship to wavelength. A spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Spectrometers may operate over a wide range of non-optical wavelengths, from gamma rays and X-rays into the far infrared. If the instrument is designed to measure the spectrum on an absolute scale rather than a relative one, then it is typically called a spectrophotometer. The majority o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective Lens
In optical engineering, the objective is the optical element that gathers light from the object being observed and Focus (optics), focuses the ray (optics), light rays to produce a real image. Objectives can be a single Lens (optics), lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample. Magn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prism (optics)
An optical prism is a transparent optics, optical element with flat, polished surfaces that are designed to refraction, refract light. At least one surface must be angled — elements with two parallel surfaces are ''not'' prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides. Not all optical prisms are prism (geometry), geometric prisms, and not all geometric prisms would count as an optical prism. Prisms can be made from any material that is transparent to the wavelengths for which they are designed. Typical materials include glass, acrylic glass, acrylic and fluorite#Optics, fluorite. A dispersive prism can be used to break white#White light, white light up into its constituent spectral colors (the colors of the rainbow) as described in the following section. Other types of prisms noted below can be used to reflection (physics), reflect light, or to split light into components with different polarization (w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction Grating
In optics, a diffraction grating is an optical component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structural coloration. The directions or diffraction angles of these beams depend on the wave (light) incident angle to the diffraction grating, the spacing or distance between adjacent diffracting elements (e.g., parallel slits for a transmission grating) on the grating, and the wavelength of the incident light. The grating acts as a dispersive element. Because of this, diffraction gratings are commonly used in monochromators and spectrometers, but other applications are also possible such as optical encoders for high precision motion control and wavefront measurement. For typical applications, a reflective grating has ridges or ''rulings'' on its surface while a transmissive grating has transmissive or hollow slits on its surface. Such a grating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroheliograph
The spectroheliograph is an instrument used in astronomy which captures a photographic image of the Sun at a single wavelength of light, a monochromatic image. The wavelength is usually chosen to coincide with a spectral wavelength of one of the chemical elements present in the Sun. It was developed independently by George Ellery Hale and Henri-Alexandre Deslandres in the 1890s and further refined in 1932 by Robert R. McMath to take motion pictures. The instrument comprises a prism or diffraction grating and a narrow slit that passes a single wavelength (a monochromator). The light is focused onto a photographic medium and the slit is moved across the disk of the Sun to form a complete image. It is now possible to make a filter that transmits a narrow band of wavelengths which produces a similar image, but spectroheliographs remain in use. See also * Spectrohelioscope * Helioscope * Heliometer A heliometer (from Greek ἥλιος ''hḗlios'' "sun" and ''measure'') is an in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helioscope
A helioscope is an instrument used in observing the sun and sunspots. The helioscope was first used by Benedetto Castelli (1578-1643) and refined by Galileo (1564–1642). The method involves projecting an image of the sun onto a white sheet of paper suspended in a darkened room with the use of a telescope. The first ''machina helioscopica'' or helioscope was designed by Christoph Scheiner (1575 –1650) to assist his sunspot observations. (Latin) In the context of modern astroparticle physics, the term ''helioscope'' can also refer to an experiment that seeks to observe hypothetical particles (such as the axion) produced inside the sun. Examples of such helioscope experiments searching for axions include the CERN Axion Solar Telescope and International Axion Observatory. See also *Solar telescope *Heliometer *Spectroheliograph *Spectrohelioscope References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
