Telescopes and Images
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Optimization of the Input Fundamental Beam by Using a Spatial Filter Consisting of Two Apertures
Journal of the Korean Physical Society, Vol. 56, No. 1, January 2010, pp. 325∼328 Optimization of the Input Fundamental Beam by Using a Spatial Filter Consisting of Two Apertures Bonghoon Kang∗ Department of Visual Optics, Far East University, Chungbuk Eumseong-gun 369-700 Gi-Tae Joo Materials Science and Technology Division, Korea Institute of Science and Technology, Seoul 136-791 Bum Ku Rhee Department of Physics, Sogang University, Seoul 121-742 (Received 17 August 2009) The primary importance of the power efficiency of second-harmonic generation (SHG) is deter- mined by using the spatial shape of the fundamental input beam, its confocal parameter. The improvement of the fundamental input beam by using a spatial filter consisting of two apertures. The beam quality factor M2 of the improved fundamental beam was about 2.3. PACS numbers: 42.62.-b, 42.79.Nv, 42.25.Bs Keywords: Second-harmonic generation (SHG), Spatial filter, Beam quality factor, Confocal parameter DOI: 10.3938/jkps.56.325 I. INTRODUCTION Beam shaping requires a specific input beam. In order for the shaping to create an undistorted flat top beam or Gaussian-like beam, the input beam must be Gaus- Second harmonic generation (SHG) is widely used in sian. If the input beam does not have the proper profile, nonlinear optical spectroscopy. The optimization of the then measurements will tell the user that adjustments power efficiency of SHG is of primary importance in a to the source beam must be made before attempting to number of applications, especially when continuous wave perform the laser beam shaping. -
Fourier Optics
Fourier Optics 1 Background Ray optics is a convenient tool to determine imaging characteristics such as the location of the image and the image magni¯cation. A complete description of the imaging system, however, requires the wave properties of light and associated processes like di®raction to be included. It is these processes that determine the resolution of optical devices, the image contrast, and the e®ect of spatial ¯lters. One possible wave-optical treatment considers the Fourier spectrum (space of spatial frequencies) of the object and the transmission of the spectral components through the optical system. This is referred to as Fourier Optics. A perfect imaging system transmits all spectral frequencies equally. Due to the ¯nite size of apertures (for example the ¯nite diameter of the lens aperture) certain spectral components are attenuated resulting in a distortion of the image. Specially designed ¯lters on the other hand can be inserted to modify the spectrum in a prede¯ned manner to change certain image features. In this lab you will learn the principles of spatial ¯ltering to (i) improve the quality of laser beams, and to (ii) remove undesired structures from images. To prepare for the lab, you should review the wave-optical treatment of the imaging process (see [1], Chapters 6.3, 6.4, and 7.3). 2 Theory 2.1 Spatial Fourier Transform Consider a two-dimensional object{ a slide, for instance that has a ¯eld transmission function f(x; y). This transmission function carries the information of the object. A (mathematically) equivalent description of this object in the Fourier space is based on the object's amplitude spectrum ZZ 1 F (u; v) = f(x; y)ei2¼ux+i2¼vydxdy; (1) (2¼)2 where the Fourier coordinates (u; v) have units of inverse length and are called spatial frequencies. -
THE STUDY of SATURN's RINGS 1 Thesis Presented for the Degree Of
1 THE STUDY OF SATURN'S RINGS 1610-1675, Thesis presented for the Degree of Doctor of Philosophy in the Field of History of Science by Albert Van Haden Department of History of Science and Technology Imperial College of Science and Teohnology University of London May, 1970 2 ABSTRACT Shortly after the publication of his Starry Messenger, Galileo observed the planet Saturn for the first time through a telescope. To his surprise he discovered that the planet does.not exhibit a single disc, as all other planets do, but rather a central disc flanked by two smaller ones. In the following years, Galileo found that Sa- turn sometimes also appears without these lateral discs, and at other times with handle-like appendages istead of round discs. These ap- pearances posed a great problem to scientists, and this problem was not solved until 1656, while the solution was not fully accepted until about 1670. This thesis traces the problem of Saturn, from its initial form- ulation, through the period of gathering information, to the final stage in which theories were proposed, ending with the acceptance of one of these theories: the ring-theory of Christiaan Huygens. Although the improvement of the telescope had great bearing on the problem of Saturn, and is dealt with to some extent, many other factors were in- volved in the solution of the problem. It was as much a perceptual problem as a technical problem of telescopes, and the mental processes that led Huygens to its solution were symptomatic of the state of science in the 1650's and would have been out of place and perhaps impossible before Descartes. -
Diffraction and Spatial Filtering P
Diffraction and Spatial Filtering P. Bennett PHY452 "Optics" Concepts Fraunhofer and Fresnel Diffraction; Spatial Filtering; Geometric optics (lenses, conjugate object- image points, focal plane, magnification); Fast-Fourier Transform; Analytic functions for N-slit apertures. Background Reading “Diffraction and Fourier Optics” (RiceUnivOpticsLab.pdf). This is an excellent write-up, particularly for theory. We follow it closely. Diffraction Physics, J. M. Cowley - definitive reference for general principles and elegant presentation. Optics, text by E. Hecht - detailed reference document with much practical information. “Geometric optics” (image formation with lenses) and “diffraction” - any UG text. Edmund Optics catalog - excellent technical info, with online tutorials and prices! SpatialFilter.xlt and *.doc Fresnel diffraction calculations (XL template and help) Special Equipment and Skills Alignment of optical components; CCD camera; Laser (Edmund P54-025, 5mW, = 635nm). Precautions Never allow the laser beam into your eye, either directly (“looking” at it) or indirectly (by spurious reflection from metal, glass, etc). Even with viewing screens, the focused spot is extremely bright, so be sure to attenuate the beam to a comfortable viewing level at all times. This will save your eyes and also the detector! Do note exceed 5V for the laser diode ($600). Handle the optical components (lenses, pinhole, apertures, slits) carefully: always store them in the vertical mounts or the wooden rack. Never lay them flat on the table, since they scratch, clog or deform easily. Lens-cleaning tissues and an air brush are available for gentle cleaning. Vinyl gloves are available for handling (mounting, etc), if necessary. Check for scratches by reflections of a bright light. -
Appendix I Lunar and Martian Nomenclature
APPENDIX I LUNAR AND MARTIAN NOMENCLATURE LUNAR AND MARTIAN NOMENCLATURE A large number of names of craters and other features on the Moon and Mars, were accepted by the IAU General Assemblies X (Moscow, 1958), XI (Berkeley, 1961), XII (Hamburg, 1964), XIV (Brighton, 1970), and XV (Sydney, 1973). The names were suggested by the appropriate IAU Commissions (16 and 17). In particular the Lunar names accepted at the XIVth and XVth General Assemblies were recommended by the 'Working Group on Lunar Nomenclature' under the Chairmanship of Dr D. H. Menzel. The Martian names were suggested by the 'Working Group on Martian Nomenclature' under the Chairmanship of Dr G. de Vaucouleurs. At the XVth General Assembly a new 'Working Group on Planetary System Nomenclature' was formed (Chairman: Dr P. M. Millman) comprising various Task Groups, one for each particular subject. For further references see: [AU Trans. X, 259-263, 1960; XIB, 236-238, 1962; Xlffi, 203-204, 1966; xnffi, 99-105, 1968; XIVB, 63, 129, 139, 1971; Space Sci. Rev. 12, 136-186, 1971. Because at the recent General Assemblies some small changes, or corrections, were made, the complete list of Lunar and Martian Topographic Features is published here. Table 1 Lunar Craters Abbe 58S,174E Balboa 19N,83W Abbot 6N,55E Baldet 54S, 151W Abel 34S,85E Balmer 20S,70E Abul Wafa 2N,ll7E Banachiewicz 5N,80E Adams 32S,69E Banting 26N,16E Aitken 17S,173E Barbier 248, 158E AI-Biruni 18N,93E Barnard 30S,86E Alden 24S, lllE Barringer 29S,151W Aldrin I.4N,22.1E Bartels 24N,90W Alekhin 68S,131W Becquerei -
Laser Beam “Clean-Up” with Spatial Filter Abstract
Laser Beam “Clean-Up” with Spatial Filter Abstract To obtain good beam quality is important for many laser applications, and a typical experimental method to obtain good beam quality is the spatial filtering. Within a spatial filtering system, a pinhole is placed on the intermediate focal plane (i.e. the Fourier plane) to get rid of the unwanted spatial frequency components. To model such systems, one must consider the diffraction from the pinhole and the diffraction property of the laser beams, and we demonstrate the spatial filtering effect in this example. 2 Modeling Task How does the size of the pinhole, located at the intermediate focal plane, influence the output beam? ? input field - wavelength lens #1 lens #2 632.8 nm feff = 25 mm feff = 25 mm - multimode laser D = 12.5 mm D = 12.5 mm with “noise” pinhole circular opening Fourier plane 3 Spatial Filter with 7.5µm-Diameter Opening A relatively large pinhole does not filter out much noise on the Fourier plane. 7.5 µm behind pinhole in front of pinhole input field pinhole 7.5 µm diameter lens #1 lens #2 4 Spatial Filter with 7.5µm-Diameter Opening 7.5 µm behind pinhole in front of pinhole input field output field pinhole 7.5 µm diameter lens #1 lens #2 5 Spatial Filter with 5.0µm-Diameter Opening 5.0 µm behind pinhole in front of pinhole input field output field pinhole 5.0 µm diameter lens #1 lens #2 6 Spatial Filter with 2.5µm-Diameter Opening 2.5 µm behind pinhole in front of pinhole input field output field pinhole 2.5 µm diameter lens #1 lens #2 7 Output Beam Profile and Power Comparison lens #1 lens #2 pinhole varying diameter Spatial filter in the Fourier plane helps reduce the higher-frequency noise, therefore leads to better output beam profiles. -
GEORGE HERBIG and Early Stellar Evolution
GEORGE HERBIG and Early Stellar Evolution Bo Reipurth Institute for Astronomy Special Publications No. 1 George Herbig in 1960 —————————————————————– GEORGE HERBIG and Early Stellar Evolution —————————————————————– Bo Reipurth Institute for Astronomy University of Hawaii at Manoa 640 North Aohoku Place Hilo, HI 96720 USA . Dedicated to Hannelore Herbig c 2016 by Bo Reipurth Version 1.0 – April 19, 2016 Cover Image: The HH 24 complex in the Lynds 1630 cloud in Orion was discov- ered by Herbig and Kuhi in 1963. This near-infrared HST image shows several collimated Herbig-Haro jets emanating from an embedded multiple system of T Tauri stars. Courtesy Space Telescope Science Institute. This book can be referenced as follows: Reipurth, B. 2016, http://ifa.hawaii.edu/SP1 i FOREWORD I first learned about George Herbig’s work when I was a teenager. I grew up in Denmark in the 1950s, a time when Europe was healing the wounds after the ravages of the Second World War. Already at the age of 7 I had fallen in love with astronomy, but information was very hard to come by in those days, so I scraped together what I could, mainly relying on the local library. At some point I was introduced to the magazine Sky and Telescope, and soon invested my pocket money in a subscription. Every month I would sit at our dining room table with a dictionary and work my way through the latest issue. In one issue I read about Herbig-Haro objects, and I was completely mesmerized that these objects could be signposts of the formation of stars, and I dreamt about some day being able to contribute to this field of study. -
The 10 Parsec Sample in the Gaia Era?,?? C
A&A 650, A201 (2021) Astronomy https://doi.org/10.1051/0004-6361/202140985 & c C. Reylé et al. 2021 Astrophysics The 10 parsec sample in the Gaia era?,?? C. Reylé1 , K. Jardine2 , P. Fouqué3 , J. A. Caballero4 , R. L. Smart5 , and A. Sozzetti5 1 Institut UTINAM, CNRS UMR6213, Univ. Bourgogne Franche-Comté, OSU THETA Franche-Comté-Bourgogne, Observatoire de Besançon, BP 1615, 25010 Besançon Cedex, France e-mail: [email protected] 2 Radagast Solutions, Simon Vestdijkpad 24, 2321 WD Leiden, The Netherlands 3 IRAP, Université de Toulouse, CNRS, 14 av. E. Belin, 31400 Toulouse, France 4 Centro de Astrobiología (CSIC-INTA), ESAC, Camino bajo del castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain 5 INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese (TO), Italy Received 2 April 2021 / Accepted 23 April 2021 ABSTRACT Context. The nearest stars provide a fundamental constraint for our understanding of stellar physics and the Galaxy. The nearby sample serves as an anchor where all objects can be seen and understood with precise data. This work is triggered by the most recent data release of the astrometric space mission Gaia and uses its unprecedented high precision parallax measurements to review the census of objects within 10 pc. Aims. The first aim of this work was to compile all stars and brown dwarfs within 10 pc observable by Gaia and compare it with the Gaia Catalogue of Nearby Stars as a quality assurance test. We complement the list to get a full 10 pc census, including bright stars, brown dwarfs, and exoplanets. -
304 Index Index Index
_full_alt_author_running_head (change var. to _alt_author_rh): 0 _full_alt_articletitle_running_head (change var. to _alt_arttitle_rh): 0 _full_article_language: en 304 Index Index Index Adamson, Robert (1821–1848) 158 Astronomische Gesellschaft 216 Akkasbashi, Reza (1843–1889) viiii, ix, 73, Astrolog 72 75-78, 277 Astronomical unit, the 192-94 Airy, George Biddell (1801–1892) 137, 163, 174 Astrophysics xiv, 7, 41, 57, 118, 119, 139, 144, Albedo 129, 132, 134 199, 216, 219 Aldrin, Edwin Buzz (1930) xii, 244, 245, 248, Atlas Photographique de la Lune x, 15, 126, 251, 261 127, 279 Almagestum Novum viii, 44-46, 274 Autotypes 186 Alpha Particle Spectrometer 263 Alpine mountains of Monte Rosa and BAAS “(British Association for the Advance- the Zugspitze, the 163 ment of Science)” 26, 27, 125, 128, 137, Al-Biruni (973–1048) 61 152, 158, 174, 277 Al-Fath Muhammad Sultan, Abu (n.d.) 64 BAAS Lunar Committee 125, 172 Al-Sufi, Abd al-Rahman (903–986) 61, 62 Bahram Mirza (1806–1882) 72 Al-Tusi, Nasir al-Din (1202–1274) 61 Baillaud, Édouard Benjamin (1848–1934) 119 Amateur astronomer xv, 26, 50, 51, 56, 60, Ball, Sir Robert (1840–1913) 147 145, 151 Barlow Lens 195, 203 Amir Kabir (1807–1852) 71 Barnard, Edward Emerson (1857–1923) 136 Amir Nezam Garusi (1820–1900) 87 Barnard Davis, Joseph (1801–1881) 180 Analysis of the Moon’s environment 239 Beamish, Richard (1789–1873) 178-81 Andromeda nebula xii, 208, 220-22 Becker, Ernst (1843–1912) 81 Antoniadi, Eugène M. (1870–1944) 269 Beer, Wilhelm Wolff (1797–1850) ix, 54, 56, Apollo Missions NASA 32, 231, 237, 239, 240, 60, 123, 124, 126, 130, 139, 142, 144, 157, 258, 261, 272 190 Apollo 8 xii, 32, 239-41 Bell Laboratories 270 Apollo 11 xii, 59, 237, 240, 244-46, 248-52, Beg, Ulugh (1394–1449) 63, 64 261, 280 Bergedorf 207 Apollo 13 254 Bergedorfer Spektraldurchmusterung 216 Apollo 14 240, 253-55 Biancani, Giuseppe (n.d.) 40, 274 Apollo 15 255 Biot, Jean Baptiste (1774–1862) 1,8, 9, 121 Apollo 16 240, 255-57 Birt, William R. -
Adams Adkinson Aeschlimann Aisslinger Akkermann
BUSCAPRONTA www.buscapronta.com ARQUIVO 27 DE PESQUISAS GENEALÓGICAS 189 PÁGINAS – MÉDIA DE 60.800 SOBRENOMES/OCORRÊNCIA Para pesquisar, utilize a ferramenta EDITAR/LOCALIZAR do WORD. A cada vez que você clicar ENTER e aparecer o sobrenome pesquisado GRIFADO (FUNDO PRETO) corresponderá um endereço Internet correspondente que foi pesquisado por nossa equipe. Ao solicitar seus endereços de acesso Internet, informe o SOBRENOME PESQUISADO, o número do ARQUIVO BUSCAPRONTA DIV ou BUSCAPRONTA GEN correspondente e o número de vezes em que encontrou o SOBRENOME PESQUISADO. Número eventualmente existente à direita do sobrenome (e na mesma linha) indica número de pessoas com aquele sobrenome cujas informações genealógicas são apresentadas. O valor de cada endereço Internet solicitado está em nosso site www.buscapronta.com . Para dados especificamente de registros gerais pesquise nos arquivos BUSCAPRONTA DIV. ATENÇÃO: Quando pesquisar em nossos arquivos, ao digitar o sobrenome procurado, faça- o, sempre que julgar necessário, COM E SEM os acentos agudo, grave, circunflexo, crase, til e trema. Sobrenomes com (ç) cedilha, digite também somente com (c) ou com dois esses (ss). Sobrenomes com dois esses (ss), digite com somente um esse (s) e com (ç). (ZZ) digite, também (Z) e vice-versa. (LL) digite, também (L) e vice-versa. Van Wolfgang – pesquise Wolfgang (faça o mesmo com outros complementos: Van der, De la etc) Sobrenomes compostos ( Mendes Caldeira) pesquise separadamente: MENDES e depois CALDEIRA. Tendo dificuldade com caracter Ø HAMMERSHØY – pesquise HAMMERSH HØJBJERG – pesquise JBJERG BUSCAPRONTA não reproduz dados genealógicos das pessoas, sendo necessário acessar os documentos Internet correspondentes para obter tais dados e informações. DESEJAMOS PLENO SUCESSO EM SUA PESQUISA. -
Increasing Estimation Precision in Localization Microscopy
INCREASING ESTIMATION PRECISION IN LOCALIZATION MICROSCOPY by Carl G. Ebeling A dissertation submitted to the faculty of The University of Utah in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physics Department of Physics and Astronomy The University of Utah May 2015 Copyright © Carl G. Ebeling 2015 All Rights Reserved The University of Utah Graduate School STATEMENT OF DISSERTATION APPROVAL The dissertation of Carl G. Ebeling has been approved by the following supervisory committee members: Jordan M. Gerton Chair 12/05/2014 Date Approved Erik M. Jorgensen Member 12/05/2014 Date Approved Saveez Saffarian Member 12/05/2014 Date Approved Stephan Lebohec Member 12/05/2014 Date Approved Paolo Gondolo Member 12/05/2014 Date Approved and by _________________ Carleton DeTar_________________ , Chair/Dean of the Department/College/School o f _____________ Physics and Astronomy__________ and by David B. Kieda, Dean of The Graduate School. ABSTRACT This dissertation studies detection-based methods to increase the estimation pre cision of single point-source emitters in the field of localization microscopy. Localiza tion microscopy is a novel method allowing for the localization of optical point-source emitters below the Abbe diffraction limit of optical microscopy. This is accomplished by optically controlling the active, or bright, state of individual molecules within a sam ple. The use of time-multiplexing of the active state allows for the temporal and spatial isolation of single point-source emitters. Isolating individual sources within a sample allows for statistical analysis on their emission point-spread function profile, and the spatial coordinates of the point-source may be discerned below the optical response of the microscope system. -
Cassini's 1679 Map of the Moon and French Jesuit Observations of the Lunar Eclipse of 11 December 1685
Cassini's 1679 Map of the Moon and French Jesuit Observations of the Lunar Eclipse of 11 December 1685 Gislén, Lars; Launay, Françoise; Orchiston, Wayne; Orchiston, Darunee Lingling; Débarbat, Suzanne; Husson, Matthieu; George, Martin; Soonthornthum, Boonrucksar Published in: Journal of Astronomical History and Heritage 2018 Document Version: Publisher's PDF, also known as Version of record Link to publication Citation for published version (APA): Gislén, L., Launay, F., Orchiston, W., Orchiston, D. L., Débarbat, S., Husson, M., George, M., & Soonthornthum, B. (2018). Cassini's 1679 Map of the Moon and French Jesuit Observations of the Lunar Eclipse of 11 December 1685. Journal of Astronomical History and Heritage, 21(2 & 3), 211-225. Total number of authors: 8 Creative Commons License: Unspecified General rights Unless other specific re-use rights are stated the following general rights apply: Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Read more about Creative commons licenses: https://creativecommons.org/licenses/ Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.