Contents PART ONE Introduction to Spectroscopy 1 Early Experiments in Spectroscopy... 3 For Further Reading............................................ 8 WebPages... 8 2 A History of Astronomical Spectroscopy... 9 Further Reading................................................ 14 WebPages... 14 3 TheoryofSpectra... 15 Kirchhoff slaws... 15 BlackBodyRadiation... 16 QuantumTheory... 17 ForbiddenLines... 18 DopplerandRedShifts... 20 SolarSpectrum... 21 StellarSpectra... 22 TheH-RDiagram... 22 HDClassifications... 23 StandardSpectralLinesandReferenceSpectra... 25 FlouroSpectrum... 26 OtherUsefulSpectralReferenceLines... 26 AiryDisk,RayleighLimits,andFWHM,PSF... 28 vii
viii Contents FocusandExitPupil... 31 ExitPupilandEyeRelief... 33 Further Reading................................................ 33 WebPages... 34 4 Prisms, Gratings and Spectroscopes... 35 Dispersion,PlateScale,andResolution... 35 EfficiencyofYourSpectroscope... 36 Prisms... 37 Resolution... 38 EfficiencyofaPrismSpectroscope... 38 AmiciPrismSystems... 39 Gratings... 39 GratingTheory... 40 Further Reading................................................ 44 WebPages... 44 5 Types of Spectroscopes... 45 ObjectivePrismorGrating... 45 PrismwithCollimator/Camera-CCD... 46 TraditionalPrismLittrow... 46 TransmissionGratinginConvergingBeam... 47 Transmission Grating in Collimated Beam (with or without Slit).... 48 Grisms... 48 ReflectionGrating(withorwithoutSlit)... 49 Further Reading................................................ 53 Webpages... 53 PART TWO Obtaining and Analyzing Spectra 6 Setting Up the Spectroscope... 57 ObjectivePrisms/Gratings... 57 CameraLenses... 57 Telescopes... 57 MountingtheObjectivePrism/Grating... 58 ObjectivePrisms... 58 ObjectiveGratings... 58 AdjustmentsandFocus... 60 Prisms... 60 Gratings... 61 FlatsandDarks... 63 WebPages... 63 7 Using Spectroscopes in the Converging Beam... 65 Obtaining Your First Spectrum................................... 67 PointstoNote... 67
Contents ix CameraResponsevs.RecordedSpectra... 68 UsingOtherTransmissionGratings... 69 UsingGratingsinaCollimatedBeam... 70 WebPages... 72 8 Reflection Grating Spectroscopes... 73 MountingtheSpectroscope... 74 GettingaStarFocusedontheSlit... 76 BeamsplittersandNon-reflectiveSlits... 77 SBIGSoftwareControlledSpectroscopes... 77 BaaderDadosSpectrograph... 79 Shelyak slhiresiii... 80 QuestarQMaxSolarSpectrometer... 81 OtherSpectroscopes... 82 TheeShelSpectrographfromShelyak... 82 TheBaaderBachesEchelleSpectroscope... 83 TheOptomechanics10C... 84 RemoteControlofSpectroscopes... 84 WebPages... 85 9 Cameras and CCD s... 87 CCDChipSize... 87 PixelSize... 87 QuantumEfficiency... 89 BayerMatrix... 89 Bias,Darks,andFlats... 92 SpectroscopeFlats... 93 Further Reading................................................ 95 WebPages... 95 10 Processing Spectra... 97 PreparingtheRawImageforProcessing... 98 GratingSpectra:LinearDispersion... 98 SmileandTilt... 99 VisualSpec(VSpec)... 100 StandardStellarSpectra... 100 StandardElementLines... 101 Obtaining a Spectral Pixel Profile............................... 101 WavelengthCalibration... 102 CameraResponse... 104 CorrectingSpectraUsingtheCameraResponseCurve... 107 UsingtheCCDQECurves ResponseCurve... 107 CalibratingUsingaReferenceLamp... 108 Resolution... 108 NormalizedSpectrum... 108 SignaltoNoiseRatio(SNR)... 108
x Contents ContinuumRemoval... 109 EquivalentWidth(LEQ)... 109 WebPages... 109 11 Amateur Spectroscope Projects... 111 SolarSpectrum... 111 AstronomicalFilters... 112 StellarClassification... 114 EmissionStars(BeandWR)... 114 DopplerShift BinaryStars/Exoplanets/Quasars... 117 VariableStars,Nova,andSupernovae... 119 Nebulae... 121 Comets... 123 Hα ObservingofSolarProminences... 124 Meteors... 125 PlanetarySpectroscopy... 127 Further Reading................................................ 129 WebPages... 129 PART THREE Spectroscope Design and Construction 12 Design Basics... 133 TheEntranceSlit... 135 ClassicSemi-fixedEntranceSlit... 138 AdjustableEntranceSlits... 139 CommercialSlits... 139 SettingtheSlitGap... 140 ProjectionMethod... 141 OtherSlitAlternatives... 142 PhotographicNegativeforSlit... 142 TheCollimator... 143 ThePrismasaDispersionElement... 144 Resolution... 147 AbbeNumbers... 148 GratingsasaDispersionElement... 148 BlazedGratings... 148 AnamorphicFactor... 150 TheImagingLens... 151 TheEyepiece/Camera/CCD... 152 AttachingandFocusingtheCamera/CCD... 153 SpectroscopeDesignSummary... 153 Assumptions... 155 Calculations... 156 ReferenceLamps... 159 TestingandCalibratingSpectroscopes... 160
Contents xi LaserCollimator... 161 TestingtheCollimatorAlignmentandFocus... 162 OpticalTesting... 162 Calibration... 163 WebPages... 165 13 Prism Spectroscope Designs... 167 ObjectivePrisms... 167 OtherPrismSpectroscopes... 169 PrismsinCollimatedBeams... 169 TraditionalPrismSpectroscope... 171 ClassicLittrowPrismSpectroscope... 172 EfficiencyofaPrismSpectroscope... 173 Further Reading................................................ 173 WebPages... 173 14 Transmission Grating Spectroscope Designs... 175 ObjectiveGratings... 175 ConvergingBeamArrangement... 175 ApertureMask... 181 Adding a Grism............................................. 182 Adding a Slit................................................ 184 Mounting Other Transmission Gratings in a Converging Beam..... 186 ImprovingResolutionwithaCollimatorLens... 188 UsingaBarlowLensasaCollimator... 189 WatkisTransmissionGratingSpectroscope... 189 TragosDesign... 190 LORISDesign... 192 Further Reading................................................ 193 WebPages... 193 15 Reflection Grating Spectroscope Designs... 195 ClassicDesign... 195 ConstructionNotes... 196 GratingAdjustments... 198 Dust... 198 LittrowDesign... 198 ConstructionNotes... 199 GratingHousingandAdjustment... 200 Camera/Focuser... 201 ReferenceLightSource... 202 SlitBackLightArrangement... 203 WPODesign... 203 Ebert-FastieDesign... 205 Czerny-TurnerDesign... 209 EchelleSpectroscopes... 209
xii Contents FiberOptics... 210 ApertureRatio,F/Ratio,andNumericalAperture(NA)... 211 FiberOpticApplications... 211 OtherAmateurDesigns... 212 Mete... 212 Kaye... 214 Glumac... 217 Bareges CCD Spectrograph (Rondi/Buil)........................ 217 Further Reading................................................ 217 WebPages... 217 16 Guiding, OAG, Beamsplitters, and Flip Mirrors... 219 Off-AxisGuiders... 219 BeamsplitterSpectroscopeApplications... 219 ModifyingaVixenFlipMirrortoaBeamsplitter... 220 FittingandAdjustingtheBeamsplitterPlate... 223 UsingtheBeamsplitter... 224 DovePrismasBeamsplitter... 224 TransferSystemsforGuideCameras... 226 SplitMirrorGuider... 226 Further Reading................................................ 228 WebPages... 228 Appendix A... 229 SuppliersofSpectroscopesandAccessories... 229 StarAnalyserGrating... 229 RainbowOpticsStarSpectroscope... 229 SGSandDSS-7Spectroscopes... 229 ShelyakLhiresIII... 230 BaaderDadosSpectrograph... 230 RigelSystems... 230 QMaxSpectrograph... 230 Gratings... 230 Prisms... 231 EntranceSlits... 231 LensesandMirrors... 231 ElectroluminescentPanels... 231 Appendix B... 233 UsefulSpectroscopyForumsandOtherWebsites... 233 Appendix C... 235 SelectedBibliography... 235 Appendix D... 237 Extras... 237 Index... 239