[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki41\/dragonfly-telephoto-array-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki41\/dragonfly-telephoto-array-wikipedia\/","headline":"Dragonfly Telephoto Array – Wikipedia","name":"Dragonfly Telephoto Array – Wikipedia","description":"From Wikipedia, the free encyclopedia Astronomical telescope built from multiple camera lenses The Dragonfly Telephoto Array is a ground-based optical","datePublished":"2019-04-20","dateModified":"2019-04-20","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki41\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki41\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/4\/49\/Canon_EF_400mm_f2.8L_IS_II_USM_lens.jpg\/240px-Canon_EF_400mm_f2.8L_IS_II_USM_lens.jpg","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/4\/49\/Canon_EF_400mm_f2.8L_IS_II_USM_lens.jpg\/240px-Canon_EF_400mm_f2.8L_IS_II_USM_lens.jpg","height":"133","width":"240"},"url":"https:\/\/wiki.edu.vn\/en\/wiki41\/dragonfly-telephoto-array-wikipedia\/","wordCount":2660,"articleBody":"From Wikipedia, the free encyclopediaAstronomical telescope built from multiple camera lensesThe 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.[1]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.  The telescope was designed by Roberto Abraham of the University of Toronto and Pieter van Dokkum of Yale University.[2] It was commissioned in 2013[1] and initially had eight commercially available Canon EF 400mm f\/2.8L IS II USM camera lenses.[3] This was first increased to ten lenses, and was extended to two clusters of 24 lenses each in 2016.[4][5][6] The array is designed to accommodate the addition of lenses to increase its effective aperture with each additional lens.[3]With 48 lenses, the instrument has a light gathering power equivalent to a 400\u00a0mm f\/0.4 lens, or a refracting telescope with an objective lens diameter of 990\u00a0mm (39\u00a0in). In March 2021 plans were announced to add 120 more lenses.[7]By using a lens based refactor design rather than a mirror based reflector design the telescope suffers less from issues introduced by diffraction and light scattering.[8] Reflector designs have more light scattering due to interactions with dust and any slight roughness on the mirror.[8] Issues with diffraction occur due to  the need to place obstructions in the optical path of reflecting telescopes.[8]Research[edit]Astronomers used the Dragonfly Telephoto Array to discover Dragonfly 44, a galaxy that is roughly as massive as the Milky Way, with 99.9% of its mass composed of dark matter.[9] At the other end of the scale it was also used to discover NGC 1052-DF2, which measurements with other instruments initially suggested was a galaxy with very little dark matter.[10] Further work indicated that NGC 1052-DF2 was closer to the earth than previous thought.[11] If this is the case then the galaxy appears to contain a typical amount of dark matter.[11]References[edit]^ a b “Dragonfly – Dunlap Institute”. Dunlap Institute for Astronomy and Astrophysics. Retrieved 5 March 2018.^ “A New Kind of Telescope”. University of Toronto Magazine. Retrieved 29 May 2020.^ a b Abraham, Roberto G.; van Dokkum, Pieter (January 2014). “Ultra \u2013 Low Surface Brightness Imaging with the Dragonfly Telephoto Array”. Publications of the Astronomical Society of the Pacific. 126 (935): 55. arXiv:1401.5473. Bibcode:2014PASP..126…55A. doi:10.1086\/674875. S2CID\u00a0119197160.^ “How Do You Make A Galaxy Without Dark Matter?”. Dunlap Institute for Astronomy and Astrophysics. Retrieved 15 Apr 2019.^ Estes, Adam C. “Astronomers Invent New Telescope by Tying Telephoto Lenses Together”. Gizmodo. Retrieved 5 March 2018.^ “Dragonfly – Yale University”. Retrieved 5 March 2018.^ Lens array captures dim objects missed by giant telescopes, Science, Vol 371 p1301 26 March 2021^ a b c Jielai Zhang (2018). The Development and Scientific Application of the Dragonfly Telephoto Array (PDF) (PhD). University of Toronto. p.\u00a010.^ “Meet Dragonfly 44, the galaxy made of 99.9% dark matter”. Wired. Retrieved 5 March 2018.^ Van Dokkum, Pieter; Danieli, Shany; Cohen, Yotam; Merritt, Allison; Romanowsky, Aaron J; Abraham, Roberto; Brodie, Jean; Conroy, Charlie; Lokhorst, Deborah; Mowla, Lamiya; o’Sullivan, Ewan; Zhang, Jielai (2018). “A galaxy lacking dark matter”. Nature. 555 (7698): 629\u2013632. arXiv:1803.10237. Bibcode:2018Natur.555..629V. doi:10.1038\/nature25767. PMID\u00a029595770. S2CID\u00a04460376.^ a b Trujillo, Ignacio (14 March 2019). “A distance of 13 Mpc resolves the claimed anomalies of the galaxy lacking dark matter”. Monthly Notices of the Royal Astronomical Society. 486 (1): 1192\u20131219. arXiv:1806.10141. Bibcode:2019MNRAS.486.1192T. doi:10.1093\/mnras\/stz771. S2CID\u00a0118889598. Retrieved 5 June 2019.External links[edit]"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki41\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki41\/dragonfly-telephoto-array-wikipedia\/#breadcrumbitem","name":"Dragonfly Telephoto Array – Wikipedia"}}]}]