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Dragonfly Telephoto Array
The Dragonfly Telephoto Array is a ground-based optical telescope array developed at the Dunlap Institute for Astronomy & Astrophysics of the University of Toronto in Canada. The array uses a combination of telephoto lenses to observe extragalactic objects. Its main purpose is to take images of ultra-low surface brightness galaxies at visible wavelengths of light. It is well suited for this purpose because its lenses have specially-coated optical glass that reduces scattered light. Design The telescope was designed by Roberto Abraham of the University of Toronto and Pieter van Dokkum of Yale University. It was commissioned in 2013 and initially had eight commercially available Canon EF 400mm f/2.8L IS II USM camera lenses. This was first increased to ten lenses, and was extended to two clusters of 24 lenses each in 2016. The array is designed to accommodate the addition of lenses to increase its effective aperture with each additional lens. With 48 lenses, the instrument has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telescope
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 visual inspection, to make a photograph, or to collect data through electronic image sensors. There are three primary types of optical telescope: * Refracting telescopes, which use lenses and less commonly also prisms (dioptrics) * Reflecting telescopes, which use mirrors (catoptrics) * Catadioptric telescopes, which combine lenses and mirrors An optical telescope's ability to resolve small details is directly related to the diameter (or aperture) of its objective (the primary lens or mirror that collects and focuses the light), and its light-gathering power is related to the area of the objective. The larger the objective, the more light the telescope collects and the finer detail it resolves. People use optical telescopes (including monoculars and binoculars) for outdoor activities such as observational as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunlap Institute For Astronomy & Astrophysics
The Dunlap Institute for Astronomy and Astrophysics at the University of Toronto is an astronomical research centre. The institute was founded in 2008 with the help of endowed gifts to the University of Toronto from David M. Dunlap and J. Moffat Dunlap, using the proceeds from the sale of the David Dunlap Observatory. The Dunlap Institute is allied with and co-located with the University of Toronto's Department of Astronomy & Astrophysics and with the Canadian Institute for Theoretical Astrophysics, and no longer has any association or connection to the David Dunlap Observatory. Research Astronomers at the Dunlap Institute investigate a variety of topics including: * the structure of the Milky Way Galaxy *cosmic magnetic fields *cosmic explosions *the large scale structure in the universe *Dark Energy * the Cosmic Microwave Background Technology & Instrumentation Telescope, instrumentation and software projects with leadership from Dunlap scientists include: *The Drago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Toronto
The University of Toronto (UToronto or U of T) is a public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institution of higher learning in Upper Canada. Originally controlled by the Church of England, the university assumed its present name in 1850 upon becoming a secular institution. As a collegiate university, it comprises eleven colleges each with substantial autonomy on financial and institutional affairs and significant differences in character and history. The university maintains three campuses, the oldest of which, St. George, is located in downtown Toronto. The other two satellite campuses are located in Scarborough and Mississauga. The University of Toronto offers over 700 undergraduate and 200 graduate programs. In all major rankings, the university consistently ranks in the top ten public universities in the world and as the top university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephoto Lens
A telephoto lens, in photography and cinematography, is a specific type of a long-focus lens in which the physical length of the lens is shorter than the focal length. This is achieved by incorporating a special lens group known as a ''telephoto group'' that extends the light path to create a long-focus lens in a much shorter overall design. The angle of view and other effects of long-focus lenses are the same for telephoto lenses of the same specified focal length. Long-focal-length lenses are often informally referred to as ''telephoto lenses'', although this is technically incorrect: a telephoto lens specifically incorporates the telephoto group. Telephoto lenses are sometimes broken into the further sub-types of short telephoto (85–135 mm in 35 mm film format), medium telephoto: (135–300 mm in 35 mm film format) and super telephoto (over 300 mm in 35 mm film format) . Construction In contrast to a telephoto lens, for any given focal len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extragalactic
Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy. The closest objects in extragalactic astronomy include the galaxies of the Local Group, which are close enough to allow very detailed analyses of their contents (e.g. supernova remnants, stellar associations). As instrumentation has improved, distant objects can now be examined in more detail and so extragalactic astronomy includes objects at nearly the edge of the observable universe. Research into distant galaxies (outside of our local group) is valuable for studying aspects of the universe such as galaxy evolution and Active Galactic Nuclei (AGN) which give insight into physical phenomena (e.g. super massive black hole accretion and the presence of dark matter). It is through extragalactic astronomy that astronomers and physicists are able to study the effects of General ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra Diffuse Galaxy
An ultra diffuse galaxy (UDG) is an extremely low luminosity galaxy, the first example of which was discovered in the nearby Virgo Cluster by Allan Sandage and Bruno Binggeli in 1984. These galaxies have been studied for many years prior to their renaming in 2015. Their lack of luminosity is due to the lack of star-forming gas, which results in these galaxies being reservoirs of very old stellar populations. Based on discoveries confirmed in 2018, this class of galaxies includes both extremes of dark matter content: Some UDGs consist almost entirely of dark matter (such a galaxy may have the same size and mass as the Milky Way but a visible star count of only 1%), while other UDGs appear to be almost entirely free of dark matter. Examples Some ultra diffuse galaxies found in the Coma Cluster, about 330 million light years from Earth, have diameters of with 1% of the stars of the Milky Way Galaxy. The distribution of ultra diffuse galaxies in the Coma Cluster is the same as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visible Spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visual perception, 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 (unit), 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. ''Excitation purity, Unsaturated colors'' such as pink, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EF 400mm F2
Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western canon, the body of high culture literature, music, philosophy, and works of art that is highly valued in the West * Canon of proportions, a formally codified set of criteria deemed mandatory for a particular artistic style of figurative art * Canon (music), a type of composition * Canon (hymnography), a type of hymn used in Eastern Orthodox Christianity. * ''Canon'' (album), a 2007 album by Ani DiFranco * ''Canon'' (film), a 1964 Canadian animated short * ''Canon'' (game), an online browser-based strategy war game * ''Canon'' (manga), by Nikki * Canonical plays of William Shakespeare * ''The Canon'' (Natalie Angier book), a 2007 science book by Natalie Angier * ''The Canon'' (podcast), concerning film Brands and enterprises * Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roberto Abraham
Roberto Abraham, FRSC (born 12 Apr 1965, Manila, Philippines) is a Canadian astronomer and is Professor of Astronomy at the University of Toronto and a Fellow of the Royal Society of Canada. Education Abraham received a Bachelor of Science from the University of British Columbia in 1987 and a PhD from Oxford University in 1992, working under the supervision of Ian M. McHardy and Roger Davies. He did post-doctoral work at the Dominion Astrophysical Observatory, the Institute of Astronomy, Cambridge and the Royal Greenwich Observatory. Career Abraham's career has been notable for his contributions via non-parametric statistics to galaxy morphological classification, especially at high-redshift and early work on the Hubble Deep Field. He was one of the leaders of the "Gemini Deep Deep Survey" which led to several notable results on early galaxies including the evolution of elliptical galaxies and why a lot of them appear so remarkably old. He is currently a co-principal-inves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pieter Van Dokkum
Pieter is a male given name, the Dutch form of Peter. The name has been one of the most common names in the Netherlands for centuries, but since the mid-twentieth century its popularity has dropped steadily, from almost 3000 per year in 1947 to about 100 a year in 2016. at the Corpus of First Names in The Netherlands Some of the better known people with this name are below. See for a longer list. * Pieter de Coninck (?-1332), Flemish revolutionary * (c. 1480–1572), Flemish Franciscan missionary in Mexico known as "Pedro de Gante" * |
Yale University
Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the world. It is a member of the Ivy League. Chartered by the Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first PhD in the United States in 1861 and organizing as a university in 1887. Yale's faculty and student populations grew after 1890 with rapid expansion of the physical campus and scientific research. Yale is organized into fourteen constituent schools: the original undergraduate col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EF 400mm Lens
The Canon EF 400mm are seven super-telephoto lenses made by Canon. These lenses have an EF mount that work with the EOS line of cameras. These lenses are widely used by sports and wildlife photographers. Canon currently manufactures four 400mm prime lenses: *EF 400mm 2.8L IS III USM *EF 400mm 2.8L IS II USM *EF 400mm 4 DO IS II USM *EF 400mm 5.6L USM The 400mm 4 DO IS II USM, which replaced an earlier version of the same lens in 2014, is one of only two Canon lenses that make use of diffractive optics (the other is the EF 70–300mm f/4.5–5.6 DO IS USM). The use of diffractive optics allows the lens to be significantly lighter than it might otherwise be. These lenses are compatible with the Canon Extender EF teleconverters. Specifications of the EF 400mm lenses Use in astronomy Canon 400 mm f/2.8 L IS II USM lenses are used in the Dragonfly Telephoto Array. The array is designed to image astronomical objects with low surface brightness such as some satellite galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
