Patrick Moore’s Practical Astronomy Series Other Titles in this Series NavigatingtheNightSky AstronomyoftheMilkyWay HowtoIdentifytheStarsand TheObserver’sGuidetothe Constellations Southern/NorthernSkyParts1and2 GuilhermedeAlmeida hardcoverset ObservingandMeasuringVisual MikeInglis DoubleStars AstronomyoftheMilkyWay BobArgyle(Ed.) Part1:Observer’sGuidetothe ObservingMeteors,Comets,Supernovae NorthernSky andothertransientPhenomena MikeInglis NeilBone AstronomyoftheMilkyWay HumanVisionandTheNightSky Part2:Observer’sGuidetothe HowtoImproveYourObservingSkills SouthernSky MichaelP.Borgia MikeInglis HowtoPhotographtheMoonandPlanets ObservingComets withYourDigitalCamera NickJamesandGeraldNorth TonyBuick TelescopesandTechniques PracticalAstrophotography AnIntroductiontoPracticalAstronomy JeffreyR.Charles ChrisKitchin PatternAsterisms SeeingStars ANewWaytoCharttheStars TheNightSkyThroughSmallTelescopes JohnChiravalle ChrisKitchinandRobertW.Forrest DeepSkyObserving Photo-guidetotheConstellations TheAstronomicalTourist ASelf-TeachingGuidetoFindingYour SteveR.Coe WayAroundtheHeavens ChrisKitchin VisualAstronomyintheSuburbs AGuidetoSpectacularViewing SolarObservingTechniques AntonyCooke ChrisKitchin VisualAstronomyUnderDarkSkies HowtoObservetheSunSafely ANewApproachtoObservingDeepSpace LeeMacdonald AntonyCooke TheSuninEclipse RealAstronomywithSmallTelescopes SirPatrickMooreandMichaelMaunder Step-by-StepActivitiesforDiscovery Transit MichaelK.Gainer WhenPlanetsCrosstheSun ThePracticalAstronomer’sDeep-sky SirPatrickMooreandMichaelMaunder Companion LightPollution JessK.Gilmour ResponsesandRemedies ObservingVariableStars BobMizon GerryA.Good AstronomicalEquipmentforAmateurs Observer’sGuidetoStellarEvolution MartinMobberley TheBirth,LifeandDeathofStars TheNewAmateurAstronomer MikeInglis MartinMobberley FieldGuidetotheDeepSkyObjects LunarandPlanetaryWebcamUser’sGuide MikeInglis MartinMobberley Making Beautiful Deep-Sky Images Astrophotography with Affordable Equipment and Software Greg Parker GregParker SchoolofElectronics&ComputerScience UniversityofSouthampton Highfield Southampton SO171BJUK personal:[email protected] CoverIllustration:M31-TheGreatAndromedaGalaxy LibraryofCongressControlNumber:2007929733 PatrickMoore’sPracticalAstronomySeriesISSN3192 ISBN-13:978-0-387-71352-6 e-ISBN-13:978-0-387-71353-3 Printedonacid-freepaper. ©2007SpringerScience+BusinessMedia,LLC Allrightsreserved.Thisworkmaynotbetranslatedorcopiedinwholeorinpartwithoutthewritten permissionofthepublisher(SpringerScience+BusinessMedia,LLC,233SpringStreet,NewYork, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use inconnectionwithanyformofinformationstorageandretrieval,electronicadaptation,computer software,orbysimilarordissimilarmethodologynowknownorhereafterdevelopedisforbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if theyarenotidentifiedassuch,isnottobetakenasanexpressionofopinionastowhetherornot theyaresubjecttoproprietaryrights. 987654321 springer.com IdedicatethisbooktomywifeHelga,whounderstandsmyobsession,andwhose favourite image was M13, but is now the wide field version of the Rosette. Contents Preface..................................................................xi Acknowledgements......................................................xiii Chapter1 How did I start?....................................... 1 Chapter2 The Beginning – and a Serious Health Warning!........15 Chapter3 Assembling your Imaging System......................19 Refractor or Reflector, or Perhaps Both?................19 Reflecting Telescope as the Main Imaging Scope.........22 Refractor as the Main Imaging Telescope ...............25 Reflector/Refractor Imaging Combination...............27 Polar Alignment ......................................28 Collimation of an SCT.................................29 The CCD Camera.....................................29 Celestron Nexstar 11 GPS SCT .........................30 Takahashi Sky 90 Refractor............................32 Sub-exposure Times...................................32 Narrowband Imaging and Light Pollution Filters.........36 Chapter4 Computational Considerations – Data Acquisition and Image Processing.................................39 vii viii Contents Chapter5 A Permanent Setup....................................45 Chapter6 First Light – Choosing your Objects....................49 Some Possible Examples...............................50 Spring................................................50 Summer..............................................52 Autumn..............................................53 Winter...............................................54 Other Things to Image ................................56 Chapter7 First Light – your First Objects.........................57 Stop Press!!...........................................60 Chapter8 Hyperstar Imaging....................................61 Sub-exposure Times with the Hyperstar.................65 The Images...........................................67 Chapter9 Wide-Field Imaging with a Short Focal Length Refractor......................................69 Chapter10 Basic Image Processing................................73 Creating the Image Processing File .....................74 Processing the Combined File Dataset ..................76 A “Quick” Process of a Single Frame of the Pleiades.....................................77 PhotoShop Processing of the Pleiades Data and Use of Noel Carboni’s Actions ..................78 Forming a Mosaic.....................................80 Chapter11 The Deep-Sky Images..................................95 Chapter12 Differentiating your Work............................1.39 Asteroid 162 Laurentia ................................145 Chapter13 Your Largest Resource................................1.47 Chapter14 Book Recommendations..............................1.53 Appendix1 The Angular Size of Objects in the Sky................1.57 Appendix2 The Designation of Deep-Sky Objects..................1.59 General Deep-Sky Objects.............................1.60 Diffuse Nebula.......................................1.60 Dark Nebulae........................................1.61 Open Clusters........................................1.61 Galaxies.............................................1.61 Galaxy Clusters.......................................162 Contents ix Physics World Article...................................................1.63 Most Amazing 21/ Hours of my Life – So Far!..........1.63 2 Greg Parker............................................................1.67 University Website Biography.........................1.68 Postscript – and a Tiny Admission .......................................171 Index..................................................................1.73 Preface I have recently discovered the most satisfying hobby so far, and to be frank, I havepursuedquiteafewhobbiesinmytime!Thisoneencompassescomputers, optics, precision mechanics, digital image processing and artistic appreciation, and it therefore satisfies just about every major interest I have in one go. The hobby is taking photographic images of the deep-sky. I have not met anyone, so far, that has not been moved, sometimes to a great extent, by the images you will find within the pages of this book. Some people willactuallyadmittobeingfrightenedbythevastnessofspacethattheseimages depict. I am not frightened by these images, but I am certainly awe-struck by them,andtheydomakemefeelratherinsignificantregardingthegrandscaleof things.Iamalsostillfirmlyinthegripofbeingtotallyamazedthatthecapability totakesuchawe-inspiringimagesisnowavailabletoanyonewithsufficienttime and effort to dedicate to this most rewarding of hobbies. This book has two aims. The first is to show you the richness, wonder, and beauty of deep-sky objects. The second is to show you how you can take these images for yourself, using readily available commercial equipment. Ireallyenvythoseofyouwhowillembarkonthisadventurefortheveryfirst time after reading the contents of this book. Savour and record every moment, it is truly a unique life-experience! Greg Parker Brockenhurst, Hampshire, U.K. 2007. xi