中星仪的机械改装和检测

本文叙述了把蔡司中星仪改装成为能灵活地在子午方向和卯酉方向交替观测的试验仪器的情况。指出仪器改装是成功的,达到了预期的要求。文中还叙述了在这架仪器上为适应新方法的需要而进行的自动化装置试验,以及检测望远镜枢轴不圆度的情况。     

库特摄谱仪的一些常用数据计算

本文计算了一米望远镜库特摄谱仪的角色散、一次拍照范围、线色散、角放大率、光谱重叠、光栅几何能量损失以及相对能量曲线等,还着重讨论了大、小准直镜的最佳使用条件。这些对进一步了解该仪器的性能以及实际使用都有用处。     

DCMT光电扫描主测微器的设计与研究

DCMT主测微器不同于其它类型的子午环测微器,它具有自校准测定仪器参数的功能。该测微器采用了活动光栅的方案,其优点是能观测近极星和各类准直像;活动光栅另一个显著优点是不同赤纬星几乎可用相同的观测时间.对“V”形光栅的工作原理和误差进行了详细讨论,并给出了一组严格的公式。其系统误差来源有:光栅形状改正、光栅驱动方向相对于光栅的倾斜、光栅驱动方向相对于赤径方向的倾斜、星径曲率改正。     

40cm水平式太阳光谱仪调试和性能测定

本文介绍了光谱仪光路装调原理、方法、步骤以及基本性能测定原理和所用设备。 给出了仪器D区光栅二级罗兰鬼线总强度约0.17％;仪器轮廓半宽为0.05A,形状基本上对称;实际分辨本领为117000;散射光总量≤2％。 装调结果达到设计要求。仪器性能良好。     

中星仪试观测结果分析

本中星仪(Zeiss No.20618)是1975年4月从北京天文台调来的。仪器到达后,即与Ⅱ型光电等高仪安装于同一临时观测室里进行校准与维护,同时开始进行光电改装试验。由于人力物力等各方面原因的影响,77年底光电改装基本结束,以后断断续续地边观测边调试,至79年4月下旬中星仪用于其他课题的试验而停观测为止,共观测     

云南暗弱天体光谱及成像仪长缝光谱研究

云南暗弱天体光谱及成像仪(Yunnan Faint-Object Spectrograph and Camera,YFOSC)是一台能够快速切换工作模式,进行天文成像及光谱观测的仪器。其中长缝光谱作为该仪器的主要光谱观测模式广泛应用于点源以及面源的分光测量研究。通过测量该模式下YFOSC系统的波长响应曲线,各块光栅的波长范围,并对定标灯谱进行波长证认,同时在考虑大气吸收以及望远镜效率的情况下给出了曝光时间曲线,为观测者更好地使用该仪器提供参考。最后以近期拍摄的一条超新星光谱为例,介绍长缝光谱模式的实际观测能力。     

中星仪改装的电路控制装置

本文叙述了在改装的中星仪上,为适应印酉方向和子午方向交叉观测的需要而装配的一套电路控制系统,以及为仪器操作自动化,试验成功的自动控制电路。     

用卯酉圈观测绝对测定子午仪的方位角

本文介绍用改装后的中星仪,分别观测同一颗星过卯酉圈和子午圈的时刻,测定仪器绝对方位角的原理和试验结果.试验在云南天文台用蔡司中星仪进行,观测结果列在表1,试验表明方法是成功的。此法用在子午环上,可替代观测拱极星的方法来测定仪器的绝对方位角,从而避免观测拱极星的困难和因用方位标过渡引进的误差。     

8~10m级光学／红外望远镜的高分辨率光谱仪

介绍并比较了KeckSubaruVLTHET及Gemini中的5架8～10m天文望远镜的高分辨率光谱仪,分析这些仪器与2～4m级望远镜的阶梯光栅光谱仪或Coude光谱仪相比所采用的新设计思想和新技术.     

光瞳光度计的改装及其误差探讨

本文描述紫金山天文台的萨尔托累型光瞳光度计(Sartorius Iris Photometer)的改装工作。用了一具带高增益放大器的示波器代替简单的调谐指示管,使平衡誤差减小,较原装置改善约7—10倍。同时,光电倍增管的供电换用一高稳定的电子稳压器,使仪器的稳定性得以改善。经过测量和比较看出湿度对漂移的影响比溫度大。此外,光电倍增管的暗流和光瞳大小也影响着漂移。还讨论了平衡誤差,得出光瞳读数取得越小,则平衡誤差也越小。最后,给出分別用改装后和原来的装置测量疏散星团IC4665中36颗星的结果。     

On the change of the inner boundary of an optically thick accretion disk around white dwarfs using the dwarf nova SS Cyg as an example

We present the results of our studies of the aperiodic optical flux variability for SS Cyg, an accreting binary systemwith a white dwarf. The main set of observational data presented here was obtained with the ANDOR/iXon DU-888 photometer mounted on the RTT-150 telescope, which allowed a record (for CCD photometers) time resolution up to 8 ms to be achieved. The power spectra of the source’s flux variability have revealed that the aperiodic variability contains information about the inner boundary of the optically thick flow in the binary system. We show that the inner boundary of the optically thick accretion disk comes close to the white dwarf surface at the maximum of the source’s bolometric light curve, i.e., at the peak of the instantaneous accretion rate onto the white dwarf, while the optically thick accretion disk is truncated at distances 8.5 × 10⁹ cm ∼10R _WD in the low state. We suggest that the location of the inner boundary of the accretion disk in the binary can be traced by studying the parameters of the power spectra for accreting white dwarfs. In particular, this allows the mass of the accreting object to be estimated.     

X‐ray energy spectra of CAL87

We present X‐ray spectral analysis of the super‐soft source CAL87 using ASCA, Chandra, XMM‐Newton observations. Early ASCA CCD spectrum reported a strong oxygen absorption edge, which is considered to originate in the an optically thick white‐dwarf atmosphere. On the other hand, contemporaneous grating observations by Chandra and XMM‐Newton indicate emission line dominated spectra, which obviously indicate the optically thin origin. Fitting all the available CCD (ASCA and XMM‐Newton) and grating spectra (XMM‐Newton and Chandra) simultaneously, we show that the CAL87 X‐ray energy spectrum is in fact composed of both an optically thick component with deep absorption edges and an optically thin component with numerous emission lines. The current result supports the standard SSS model that the primary source of X‐ray emission is nuclear burning in the white dwarf atmosphere, surrounded by a highly photoionised, optically thin corona (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

云南天文台1m望远镜卡焦(缩焦)CCD测光系统的初步研究

用云台１ｍ望远镜镜卡焦（缩焦）ＣＣＤ测光系统对测光标准星进行了ＢＶＲＩ四色测光,计算得到了该系统的转换方程及其转换结果,并对计算结果进行了分析讨论．     

A Method for Determining Precisely the Barycentric Position of Uranus Observed with CCD Systems

A method for determining precisely the barycentric position of Uranus by CCD systems is presented in this present article. It is required according to the method that the CCD observations obtained both with a long-focus telescope which is used to observe the major satellites of Uranus and with a meridian circle which works in a CCD drift scanning manner when it is used to observe some faint stars. The key part of the method is tested by the observations obtained with the 1-meter telescope at the Yunnan Observatory. This revised version was published online in July 2006 with corrections to the Cover Date.     

1991年7月11日墨西哥日全食红外光谱观测及初步结果

本文概述１９９１年７月１１日日全食时中国日食观测队在墨西哥ＬａＰａｚ所作的近红外光谱观测情况及得到的初步结果。观测是用一强光力望远镜和一中小色散的光谱仪，配以ＣＣＤ摄象机、图象处理器、微机等组成的探测系统进行的。日全食时，在λ１０７１２－１０９７２波区共摄得极上层光球和色球的无缝光谱４１帧。日面外约１．０９６Ｒ处的有缝光谱３５帧。文中还介绍了拍得的色球、日珥资料概况。     

基于CCD提高射电望远镜极轴校准精度及修正

射电望远镜极轴的安装定位是否准确直接影响其指向精度和成像质量,通过运用光学CCD原理精确测量射电望远镜极轴偏差角度,用以安装校准极轴,达到提高射电望远镜指向精度和成像质量的效果,并且结合计算机可实现多极轴同时校准,提高工作效率。同时,基于CCD技术可以及时发现天线极轴出现的偏差并进行修正,提高了数据的质量。     

CCD离焦对现代日晕光度计测量结果影响分析

现代日晕光度计（Sky Brightness Monitor,SBM）是一种测定天文址点白昼大气参量的精密仪器,它已成为国际上太阳选址工作的重要设备之一。与国外同类设备不同的是,云南天文台研制的现代日晕光度计上的CCD相机系统可以被简单拆卸并保存,有利于选址踏勘阶段的携带和运输。为获取组装现代日晕光度计设备时可能存在的CCD离焦所导致的测量误差,于2011年6月在新疆奇台县和宁夏石嘴山市利用当地稳定的日照条件做了多次CCD大离焦量快变试验。统计结果表明,现代日晕光度计的CCD显著离焦可造成的相对测量误差约在6％之内。在正常情况下,即观测者基本按照物镜旋筒刻线标志在望远镜上安装CCD设备时,日晕测量的相对误差一般远小于6％。因此认为这种系统误差对优良址点的测量影响基本可以忽略。     

Installation of solar chromospheric telescope at the Indian Astronomical Observatory,Merak

We report the observations of the solar chromosphere from a newly commissioned solar telescope at the incursion site near Pangong Tso lake in Merak (Leh/Ladakh). This new \(\hbox {H}_{\alpha }\) telescope at the Merak site is identical to the Kodaikanal \(\hbox {H}_{\alpha }\) telescope. The telescope was installed in the month of August 2017 at the Merak site. The telescope consists of a 20-cm doublet lens with additional re-imaging optics. A Lyot filter with 0.5 Å passband isolates the Balmer line of the hydrogen spectra to make the observations of the solar chromosphere. The observations made in \(\hbox {H}_{\alpha }\) wavelength delineates the magnetic field directions at the sunspot and the quiet regions. A CCD detector records the images of the chromosphere with a pixel resolution of 0.27\(^{\prime \prime }\) and covers 9.2\(^{\prime }\) field-of-view. This telescope has a good guiding system that keeps the FoV in the intended position. We report the development of control software for tuning the filter unit, control detector system, observations and calibration of the data to make it useful for the scientific community. Some preliminary results obtained from the Merak \(\hbox {H}_{\alpha }\) telescope are also presented. This high altitude facility is a timely addition to regularly obtain \(\hbox {H}_{\alpha }\) images around the globe.     

Precise Determination of the Orientation of the Solar Image

Accurate heliographic coordinates of objects on the Sun have to be known in several fields of solar physics. One of the factors that affect the accuracy of the measurements of the heliographic coordinates is the accuracy of the orientation of a solar image. In this paper the well-known drift method for determining the orientation of the solar image is applied to data taken with a solar telescope equipped with a CCD camera. The factors that influence the accuracy of the method are systematically discussed, and the necessary corrections are determined. These factors are as follows: the trajectory of the center of the solar disk on the CCD with the telescope drive turned off, the astronomical refraction, the change of the declination of the Sun, and the optical distortion of the telescope. The method can be used on any solar telescope that is equipped with a CCD camera and is capable of taking solar full-disk images. As an example to illustrate the method and its application, the orientation of solar images taken with the Gyula heliograph is determined. As a byproduct, a new method to determine the optical distortion of a solar telescope is proposed.     

厚片CCD的数据转换及初步分析

云台厚片CCD光谱系统自建立以来,基本上还只是一个封闭的系统:储存在5吋软盘中的数据只能在该系统的计算机中读出和简单处理,但该系统的计算机硬件和软件均不能满足现代光谱处理的要求。本文在将厚片CCD光谱资料转换到VAX计算机的基础上,对资料转换及其必要性以及该光谱系统的硬、软件配置进行了初步的分析与讨论。