超轻量镜面系统的研制

空间望远镜的研制一直要求系统的轻量化,美国宇航局(NASA)最近研制的韦伯太空望远镜,其主镜系统面密度相对于哈勃空间望远镜已大幅减轻.在韦伯望远镜主镜系统的研制过程中,NASA开展了一系列关于超轻量镜面系统的验证计划,多家机构拿出多个方案参与竞标.本文选取几个比较典型的方案,介绍这些镜面系统的设计思想、结构、材料、加工以及相关测试结果,期望能对国内相关方面的工作提供参考.     

一个巨型望远镜方案

提出一个有特色的巨型望远镜(FGT)方案．其主镜口径为30米，主焦比为1．2，由1095块圆环形子镜构成．采用地平式装置．光学系统包括Nasmyth系统、折轴(Coude)系统和一个大视场系统．提出一个由4个镜面组成的新的Nasmyth系统，在约10′的视场范围内像斑小于爱里斑，达到衍射极限．比传统的Nasmyth系统的衍射极限视场大得多．可在这样的大视场内同时作好几个小区域的衍射极限的观测．当由Nasmyth系统转换到折轴系统和大视场系统时，采用主动光学技术改变子镜的面形、倾斜和平移，产生一个新的主镜面形，使折轴系统和大视场系统都能得到很好的像质．大视场系统的视场直径25′，场曲轻微，并有可能校正大气色散．给出了子镜面形和位置的公差，并讨论了望远镜的装置和结构,方案中的特色和创新对未来大望远镜的研制有普遍意义．     

一种新的10米光学/红外望远镜

结合中国的实际情况提出了一 新的中国２１世纪的１０米光学／红外望远镜的方案,它是属于一种非常规概念设计的望远镜。这种新的大望远镜方案吸收了或主要参考了Ａｒｅｃｉｂｏ射电望远镜、美国的ＨｏｂｂｙＥｂｅｒｌｙ９米望远镜和ＬＡＭＯＳＴ方案的前身一光谱巡天望远镜方案。它的主镜是六角形子镜拼成的球面,在观测过程中主镜不动,由焦面的改正镜做跟踪,造价约为同样口径的常规设计望远镜的五分之一,并能满足绝大部分天文     

大型拼接镜面望远镜子镜装卸装置的研究

自从400 yr前伽利略第1次使用望远镜观测天空以来,人类为了探索更深的宇宙,望远镜的口径越做越大,拼接镜面望远镜成为趋势.本世纪初一批大口径拼接望远镜先后被研制出来,这其中包括我国的大天区面积多目标光纤光谱天文望远镜LAMOST.随着望远镜口径增大,子镜单元增多,子镜单元的装卸问题日益突出.本文试图对这一问题进行探讨,设计了一套用于LAMOST球面主镜的子镜单元装卸装置,希望为大口径望远镜的子镜装卸提供一些思路和借鉴.     

主动光学—新一代大望远镜的关键技术

对主动光学技术在现代天文光学望远镜中的作用和工作原理作了较全面的介绍和评化,结合作者近十年的工作对薄镜面主动光学技术和拼接镜面主动光学技术的各个关键部分,如波前检测,波前拟合,校正力的确定,共焦和共同的检测作了较详细且深入的讨论和评述,也介绍了我国目前正在研制的同时采用薄镜面主动光学和拼接镜面主动光学技术的大天区面积多目标光纤光镜望远镜的主动光学系统。     

第二十三届国际天文奥林匹克竞赛理论试题

如你所知,当你旋转一个装有水银的容器时,水银的表面将形成一个抛物面。所形成的液体镜面可以被用作一个望远镜的主镜面。一个北极熊天文学家决定在北极点上用这一办法制作一个望远镜,在这里它利用了地球的自转,所以这个主镜有一个长的焦距。     

未来的地面和空间大望远镜以及我国目前的大项目

目前 ,已有 1 0架口径 8～ 1 0m的地面大望远镜建成并投入科学观测。在近红外波段 ,自适应光学和干涉术已在大望远镜上获得成功。Hubble空间望远镜发射至今已逾 1 2年。为了研究早期宇宙 ,探测类地行星等 ,2 0 0 2年 9月NASA已与TWR公司签约 ,研制口径≥ 6m的下一代空间望远镜JWST ,计划2 0 1 0年发射。许多口径 30～ 1 0 0m的地面未来巨型望远镜FGT项目已经提出。本报告 ,也介绍了我国正在研制或预研中的三个大项目 :LAMOST、FAST和SST ,这些项目虽较小 ,但完成后都会对天文学的一个方面作出有份量的贡献。最后 ,报告人建议我国参与到与国外合作研制FGT或NGST的工作中 ,特别强调要有天文学家和工程专家参与进去     

空间太阳望远镜1m主镜支撑结构的研究

本文对正在预研中的空间太阳望远镜的关键部件之一1m主镜，提出一种合理的支撑结构系统，此系统可以兼顾空间太阳望远镜光学系统的地面装校调试的有效性和火箭发射力学环境中的安全性以及入轨后正常观测时的高精度性。     

一种新型轻量化反射镜结构及其在空间望远镜相关跟踪摆镜上的应用研究

本文提出一种新的反射镜轻量化方案。此方案在结构特征和减重比例上接近蜂窝结构,减重效果比背面开孔的镜子和拱形镜要好得多;同时又可避免蜂窝镜的制造难度。另外,本文还就此方案在空间太阳望远镜(SST)的相关跟踪摆镜上的应用进行探讨,给出了主要结构参数和镜面变形分析结果,其结果表明,此轻量化平面镜能满足SST的使用要求。     

多镜面望远镜：过去,现在和将来

本文阐述了多镜面望远镜(MMT)的发展简史、望远镜的功能和在望远镜上使用的终端仪器。还包括了望远镜的使用讯息、天气条件以及将来的计划。     

The James Webb Space Telescope and its Infrared Detectors

The James Webb Space Telescope (JWST) was conceived as the scientific successor to the Hubble Space Telescope (HST) and Spitzer Space Telescope. The instrument suite provides broad wavelength coverage and capabilities aimed at four key science themes: 1) The end of the dark ages: first light and reionization, 2) The assembly of galaxies, 3) The birth of stars and protoplanetary systems, and 4) Planetary systems and the origins of life. To accomplish these ambitious goals, JWST's detectors provide state-of-the-art performance spanning the λ = 0.6–28 μm wavelength range. In this paper, we describe JWST with an emphasis on its infrared detectors.     

The European HST science data archive

The design of the Data Management Facility (DMF), the system to handle the data from HST, has been based on the concepts of modularity and flexibility, so that changes inevitably due to occur during the long lifetime of the project could be gracefully accomodated. At the Space Telescope European Coordinating Facility (ST-ECF), new constraints have led the archive group to evolve the system, so to allow a more efficient ingesting of the data imported from the Space Telescope Science Institute (STScI), an easier browsing of the HST catalogue of observations, and a more efficient servicing of archive researchers' retrieval requests. In this paper, the European Science Data Archive of HST data is described, with particular reference to dataflow, hardware and software system structure, operations, differences with DMF, and foreseen developments.Affiliated with the Astrophysics Division, Space Science Dept., ESAThe observations of the NASA/ESA Hubble Space Telescope are obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.     

“Spektr-UF” project

The “Spektr-UF” project is intended for the design and development of a large space observatory operating in the ultraviolet (UV) band of the spectrum inaccessible for survey from the surface of the Earth. The main observatory instrument is a space telescope T-170M with a primary mirror 1.7 m in diameter; it will be equipped with high and low resolution spectrographs and cameras for high-quality UV imaging. In respect of capabilities, the project is similar to the American Hubble Space Telescope (HST), and exceeds the latter in some parameters. The project is included in the Russian Federal Space Program for the period 2006–2015. The launch is planned for 2016. The project is under development by the Lavochkin Association in cooperation with the Institute of Astronomy, Russian Academy of Sciences.     

The Next Generation Space Telescope

The design life time of the Hubble Space Telescope will nominally end in 2005. Even though it might be possible to extend the operational life beyond that date it is evident that a successor to Hubble must be planned for now. Based on the report ‘HST and Beyond’ (Dressler 1996)) and aligned with the NASA ‘Origins’ program a study has been initiated to explore options for a telescope with an aperture of larger than 4 meters and possibly as large as 8 meters, optimized for the near infrared (≈ 1-5 micron) to be placed in an orbit far from Earth. The study started in December 1995 and has been proceeding with considerable momentum. At the current time three studies have been completed (NASA in-house, TRW, and Lockheed), which are being used to explore technological and programmatic challenges. The studies are to be merged. It is impressive to see what can be done with existing technology and within the capabilities of existing organizational arrangements. The goal is to complete the study within one year with the goal of entering into phase A as soon as possible. Formal agreements between ESA and NASA will have to be negotiated if Europe is to play a meaningful role in this exercise. Without such agreements, it is clear that European astronomers will not have access to the NGST in the way that they currently enjoy the opportunities provided by the HST. This revised version was published online in July 2006 with corrections to the Cover Date.     

Prospects for astrometry with the Hubble Space Telescope

The Hubble Space Telescope (HST), a large optical telescope having an aperture of 2.4 meters and a length of 8.8 meters, is being developed by the National Aeronautics and Space Administration. This telescope will be placed into earth orbit by the space shuttle. Astrometric observations with the HST are made using a Fine Guidance Sensor which is capable of measuring the position of one object relative to another with an accuracy of ±0.002 arcseconds. The astrometric user of HST will be provided with an Astrometric Data Reduction Software package (ADRS). The variety of astrometric problems to be investigated with HST is discussed.     

Scientific Research using the Electronic Archive of the Hubble Space Telescope

The Hubble Space Telescope (HST), a collaborative project between the US National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) has been operating since 1990. The European HST Science Data Archive, operated at the Space Telescope European Coordinating Facility(ST-ECF) in Garching, Germany, contains all data taken with the scienceinstruments of the HST. The services of the Archive include data browsing,preview, retrieval and re-calibration. Access to the Archive is providedthrough the World Wide Web, data distribution is through the Internet oron bulk media.This paper describes the data products, access to theArchive services, and the procedures for the use of the HST Science DataArchive by qualified scientists from remote locations. The Archive providestools implemented as Java Applets which can be used over the Net. For moresophisticated operations access to a suitable data analysis system isrequired; such software can be downloaded from our site.     

Prospects of stellar abundance studies from near‐IR spectra observed with the E‐ELT

In 2006 ESO Council authorized a Phase B study of a European AO‐telescope with a 42 m segmented primary with a 5‐mirror design, the E‐ELT. Several reports and working groups have already presented science cases for an E‐ELT, specifically exploiting the new capabilities of such a large telescope. One of the aims of the design has been to find a balance in the performances between an E‐ELT and the James Webb Space Telescope, JWST. Apart from the larger photon‐collecting area, the strengths of the former is the higher attainable spatial and spectral resolutions. The E‐ELT AO system will have an optimal performance in the near‐IR, which makes it specially advantageous. High‐resolution spectroscopy in the near‐infrared has, however, not been discussed much. This paper aims at filling that gap, by specifically discussing spectroscopy of stellar (mainly red giant), photospheric abundances. Based on studies in the literature of stellar abundances, at the needed medium to high spectral resolutions in the near‐infrared (0.8–2.4 μm), I will try to extrapolate published results to the performance of the E‐ELT and explore what could be done at the E‐ELT in this field. A discussion on what instrument characteristics that would be needed for stellar abundance analyses in the near‐IR will be given (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

High resolution imaging of Pluto and Charon with the Faint Object Camera of the Hubble Space Telescope

Images of the Pluto-Charon system were obtained with the Faint Object Camera (FOC) of the Hubble Space Telescope (HST) with the aim of determination of radii, fluxes, and albedos. The resolution of the already diffraction limited images was further improved by image restoration, yielding indications of surface albedo distributions which are qualitatively consistent with models derived from observations of Pluto-Charon mutual eclipses.Based on Observations with the NASA-ESA Hubble Space Telescope, which is operated by AURA, Inc., under NASA contract NAS 5-26555.     

An image drift compensation system for a solar pointed space telescope

An Image Drift Compensation System has been designed for a solar pointed space borne telescope and has performed successfully on two sounding rocket flights, yielding new scientific results. The system employs limb-sensing photodiodes at the telescope focal plane and provides drift compensation to better than 0.1 arc sec. A variation of the system will be used on the Shuttle/Spacelab 2 flight of the High Resolution Telescope and Spectrograph (HRTS) Instrument.Originally submitted to the journalSpace Science Instrumentation.