天文望远镜简介.ppt

ThelargestrefractortelescopebuiltistheoneatYerkesObservatory，installedin1897.Ithasanobjective1.02meters(40inches)acrossatoneendofa19.2-meter(63feet)tube.Newtoniantelescopeisaparticularlypopulardesignforsmallerreflectingtelescopes,suchasthoseusedbyamateurastronomers.Astronomersmaychoosetoworkonarearplatformwheretheycanuseequipment,suchasaspectroscope,thatistooheavytohoisttotheprimefocus.Inthiscase,lightreflectedbytheprimarymirrortowardtheprimefocusisinterceptedbyasmallersecondarymirror,whichreflectsitbackdownthroughasmallholeatthecenteroftheprimarymirror.ThisarrangementisknownasaCassegraintelescope(afterGuillaumeCassegrain,aFrenchlensmaker).Athird,muchsmaller,mirrorthenreflectsthelightintoanenvironmentallycontrolledlaboratory.Knownasthecoudéroom(fromtheFrenchwordforbent),thislaboratoryisseparatefromthetelescopeitself,enablingastronomerstouseveryheavyandfinelytunedequipmentthatcouldnotpossiblybeliftedtoeithertheprimefocusortheCassegrainfocus.Thelightpathtothecoudéroomliesalongtheaxisofthetelescopesmount—thatis,theaxisaroundwhichthetelescoperotatesasittracksobjectsacrossthesky—sothatthelightpathdoesnotchangeasthetelescopemoves.第四章天文望远镜01折射望远镜：利用光线通过凸透镜的折射聚光形成光路。反射望远镜：利用曲面反射镜聚光形成光路。折反射望远镜：用球面反射镜为聚光主镜，在主镜前加一特殊形状的改正透镜，用来改进球面镜的成象条件。02034.1、光学望远镜的分类1、折射望远镜伽利略式：正像，视场小，不能安装叉丝。开普勒式：视场大，便于安叉丝，反像。物镜、目镜由不同折射率的光学玻璃复合成的。折射望远镜：?用透镜作物镜的望远镜伽利略望远镜光路图开普勒望远镜光路图????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????1897年制造的1.02米（美国叶凯士天文台）的折射镜仍是世界之最。主焦点式：反射镜为抛物面01牛顿式：反射镜为球面镜，加上平面镜02卡赛格林式：主镜为抛物面镜，副镜为凸的双曲面镜03R—C系统：凹双曲+凸双曲（改进型）04折轴式：加入几块平面镜使光束从极轴方向射出052、反射望远镜反射望远镜的

主焦点式反射镜为抛物面牛顿式反射镜为球面镜卡塞格林式抛物面、凸的双曲面镜。折轴式球面反射镜+复杂的折射改正透镜。施密特式：