Telescope-Objective-and-Eyepiece望远镜的物镜与目镜ppt课件

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Observatories and Telescopes,Mauna Kea,Hawaii(14,000 ft),Why do telescopes need to be located at high altitude and dry climate?,Observatories and TelescopesM,1,Telescopes Mirrors and Lenses,Telescopes are basically a large mirror(,reflecting,)or a lens(,refracting,),Consider the human eye as telescope,What determines the“power”of a telescope?,Telescopes Mirrors and Lense,2,Collecting Area,Lens,Retina,Eye could be a“refracting”telescope,but the size is very small,Collecting AreaLensRetinaEye c,3,Collecting Area=Power,A=,p(,d,/2),2,;d diameter,Diameter of the telescope indicates its power,Largest optical telescope:Keck 1 and 2,each with a mirror of 10 m diameter,Large Binocular Telescope(LBT):,Ohio State,Arizona,Germany,Italy,Two 8.4 m mirrors in a binocular shaped mount,HST Only 2.4 m,but with a huge advantage,How much more powerful than HST is the Keck(neglecting that advantage)?,New 30m telescope on the drawing board,Collecting Area=Power A=p,4,Large Binocular Telescope,Mount Graham,Arizona,Large Binocular TelescopeMoun,5,Telescope-Objective-and-Eyepiece望远镜的物镜与目镜ppt课件,6,Objective and eyepiece,Objective and eyepiece,7,Telescope,Objective and Eyepiece,The main function of a telescope is to collect as much light as possible from the source,NOT to magnify an image,Need bigger and bigger telescopes!,The main mirror or lens of a telescope is called the,OBJECTIVE,The,Eye-Piece,(small lens or mirror)is to magnify the image after it is formed from the light collected by the objective,Telescope Objective and Eyep,8,Properties of Light and Telescopes,Reflection,Mirrors,Refraction,Lenses,Properties of Light and Telesc,9,Simple,Refracting,Telescope,Objective Lens,Secondary Lens,(Eyepiece),Focus,Convex lens,Simple Refracting TelescopeObj,10,Spheres of light from distant source,parallel rays at the observer,Spheres of light from distant,11,Different speeds in different media,Bending or Refraction,Different speeds in different,12,Refraction of light beam,Light bends towards the perpendicular going into denser medium,and vice-versa,Normal,(Perpendicular),Refraction of light beamLight,13,Refraction by prism and lens,Refraction by prism and lens,14,Refractive Index,Speed of light slows down in a medium!,The ratio of the speed of light in vacuum to the speed in a medium,c/v=,m,mu is called the,Refractive Index,Material R.I.,Water 1.33,Glass 2.6,Bending of light(diffraction)depends on R.I of the medium and wavelength of light,l,Refractive Index Speed of ligh,15,Chromatic Aberration:,Different colors at different focus,Chromatic aberration affects,refracting,telescopes;,therefore use,reflecting,telescopes in modern observatories,Chromatic Aberration:Differen,16,Law of Reflection:Angle i=Angle r,Law of Reflection:Angle i=A,17,Primary,Mirror,Prime,Focus,Secondary,Mirror,Cassegrain,Focus,REFLECTING,TELESCOPES,PrimaryPrime Secondary Cassegr,18,Reflecting Concave Mirror,Reflecting Concave Mirror,19,Telescopic Configurations,Telescopic Configurations,20,Spherical and Parabolic Mirrors,Spherical and Parabolic Mirror,21,Wavelength range of observatories and telescopes,Ground based,telescopes can measure,-Visible(4000-7000 A),-Near-IR(0.7-2 microns),1,m,m=10000 A,-Radio(1 mm or greater),All other wavelengths blocked out by the atmosphere,Space based,observatories for Gamma ray,X-ray,UV,and Far-IR astronomy,Wavelength range of observator,22,Visible(Optical)and Radio“Windows”in the Atmosphere,Visible(Optical)and Radio“W,23,Radar and Radio Astronomy,Radio telescopes,(like huge satellite dish)collect radio waves from astronomical objects,Radar telescope,=Transmitter+Radio Telescope,Doppler Radar,Transmits radio waves towards an object and collects reflected radio waves;spread in signal shows distance and velocity,Largest,radio,telescope is the Arecibo,1000 ft diameter,in Puerto Rico,Radar and Radio Astronomy Radi,24,Radio Telescope,Radio Telescope,25,Aracebo Radio Telescope(Puerto Rico),Aracebo Radio Telescope(Puerto,26,Rotational Speed and Doppler Shift,(Line profile broadens on both the blue and red side),Doppler Radar,Rotational Speed and Doppler S,27,Hubble Space Telescope,Hubble Space Telescope,28,Ground and HST images,Unresolved,Resolved,Ground and HST imagesUnresolve,29,Visible and IR images of Saturn,Visible and IR images of Satur,30,Gamma-Ray View of the Sky,Each wavelength band presents a different and mutually complementary view,Gamma-Ray View of the SkyEach,31,Telescope and Instruments,Telescope and Instruments,32,Intensities of Lines in Absorption Spectra:Atoms absorb energy,Emission spectra are a set of bright lines:atoms emit energy,Intensities of Lines in Absorp,33,Observing Planets and Moons,Observing Planets and Moons,34,Spectra of Titan(Moon of Saturn):Methane(CH4),Spectra of Titan(Moon of Satu,35,