白日视宁度监测仪和在抚仙湖的初步观测结果

报导了用南方基地云南天文台太阳差分像运动视宁度监测仪和美国国立太阳天文台的太阳闪烁仪,在云南省澄江县抚仙湖老鹰地红外太阳塔选址点进行的对比观测,简要地介绍了这两种视宁度测量方法的原理,对观测的初步结果进行了分析。     

山东大学威海天文台视宁度研究

山东大学威海天文台拥有口径1 m的赤道式反射光学望远镜,于2007年6月建成并投入使用。对天文台2008年、2009年的所有观测数据用编写的IRAF自动处理程序进行处理得到了大气视宁度值,对得到的大气视宁度进行了分析研究,并与天文台气象站获得的气象数据一起进行了分析。经分析得到了山东大学威海天文台的大气视宁度状况,同时得到了一些大气视宁度随气象因素变化的规律。     

云南天文台丽江高美古和昆明的大气视宁度研究

研究云南天文台昆明凤凰山和丽江高美古两地点的大气视宁度。利用云南天文台于1994年建立的3孔较差视宁度监视仪（3孔DIMM），对这两个地点的视宁度对比观测。还利用云南天文台的1米望远镜所得到的视宁度与3孔DIMM所测的视宁度进行对比。1米望远镜和3孔DIMM同时观测了7个晚上，各取得308组数据，它们的视宁度平均分别为0．90〃和0．84〃。还讨论了3孔DIMM采用不同曝光时间对视宁度测量值的影响，从实验得出3孔DIMM采用20ms曝光比采用8ms曝光所测视宁度的值要好15％左右。从1995年5月－1996年12月，对丽江高美古和昆明凤凰山二地进行了视宁度的对比观测。在高美古和昆明分别观测了234夜和256夜，观测结果是两个点的视宁度平均；丽江为0．70〃，昆明为0．95〃，同时也统计了两个点的月平均视宁度和最好夜的视宁度，并讨论了两地视宁度随时间的变化规律。     

云南天文台大气视宁度观测和初步探讨

介绍了为云南丽江高美古选址点作对比的云南天文台点的大气视宁度观测统计和结果，对观测过程中的有关问题作了初步探讨。对高美古和云南天文台的１９９５年５月和１９９５年１２月２０日观测资料作了对比，结果表明：高美古选址点的视宁度明显优于云南天文台。     

丽江高美古的天文观测条件

综述对丽江高美古的视宁度、天光亮度、消光系数进行观测的原理、仪器、观测方法和结果．结果表明,高美古是我国南方的优良光学天文台址,视宁度达到世界优良台址的水平     

高美古的大气视宁度

报导了2000年和2001年丽江高美古所观测到的大气视宁度,文中统计了14个晚上的观测数据,得到的平均视宁度为0.97″,变化在0.73″～1.42″之间。这些视宁度值是用国际上天文台站测大气视宁度通用的DIMM方法,采用8ms单幅采样曝光取得的。本文还统计了丽江高美古1995年以来每年12月份的大气视宁度,可以看到高美古不同年份大气视宁度的部分变化情况。     

高美古的大气视宁度

报导了2000年和2001年丽江高美古所观测的大气视宁度，文中统计了14个晚上的观测数据，得到的平均视宁度为0.97″，变化在0.73″～1.42″之间，这些视宁度值是用国际上天文台站测大气视宁度通用的DIMM方法，采用8ms单幅采样曝光取得的。本文还统计了丽江高美古1995年以来每年12月份的大气视宁度，可以看到高美古不同年份大气视宁度的部分变化情况。     

三孔较差视宁度仪的对比观测

三孔较差视宁度仪（ＤＩＭＭ）已在丽江高美古和云南天文台投入观测，我们用云南天文台的一米望远镜测得的视宁度与ＤＩＭＭ所测得的视宁度进行对比。１９９５年上半年获得了５个晚上的资料，测得的结果表明ＤＩＭＭ测量的视宁度与一米望远镜测量的视中度是相关的。二套ＤＩＭＭ也进行了相互校正和对比，共用了８个晚上获得１２５组ｒ０，二套ＤＩＭＭ的视宁度测量值是相关的，二套系统的误差小于１％。     

三孔较差视宁度监视仪及试观测报告

本文介绍了云南天文台研制的三孔较差视宁度监视仪，统计了１９９４年３月至７月期间的试观测情况，及仪器定标和数据处理结果。     

三孔较差视宁度监视仪的原理和误差分析

本文叙述了较差视宁度监视仪的基本原理，及云南天文台研制的三个光瞳较差视宁度监视仪，并讨论了各种可能的误差。     

红外太阳塔抚仙湖老鹰地选址

介绍红外太阳塔抚仙湖老鹰地选址点的初步观测结果以及白日视宁度监测仪－“太阳差分像运行监测仪和闪仪的原理结构及用这两套仪的抚仙湖老鹰地红外太阳塔选址点进行的对比观测实验。     

Stokes II — A new polarimeter for solar observations

A Stokes polarimeter has been built at the High Altitude Observatory to obtain line profiles in both linear and circular polarization in solar spectral lines. These measurements are interpreted using the theory of radiative transfer in the presence of a magnetic field to obtain vector magnetic fields on the solar disk and using the theory of resonance scattering and the Hanle effect to obtain vector magnetic fields in prominences. The polarimeter operates on the Sacramento Peak Observatory 40 cm coronagraph. It is an extensively modified and improved version of an earlier instrument.Polarization modulation is achieved by two KD^*P Pockels cells at the coronagraph prime focus and demodulation is by a microprocessor. The instrument control and data handling is done by a minicomputer. Silicon photodiode 128 element line array detectors have replaced the two photomultipliers used on the earlier instrument. This gives a speed increase of a factor of 50.A polarization scrambler provides a chop to a reference beam of unpolarized light by time scrambling the polarization of the solar beam. This device improves sensitivity to polarizations less than 0.01%. The polarization measurements are photon noise limited in most cases. This noise is 0.1% for a typical three second observation which is about one gauss on the longitudinal field and 10 gauss on the transverse field.The National Center for Atmospheric Research is sponsored by The National Science Foundation.     

The Lyot-coronagraph with 53 cm objective

The new Lyot-coronagraph with 53 cm objective is described. The coronagraph has a grating spectrograph. The solar disk image on the slit of the spectrograph is 12.6 cm. The dispersion is 1 Å/mm in the second order. The coronagraph is situated at the Kislovodsk Station of Pulkovo Observatory, 2050 m above sea level.     

New vacuum solar telescope and observations with high resolution

The New Vacuum Solar Telescope(NVST) is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown.     

A novel quadruple beam imaging polarimeter and its application to Comet Tanaka-Machholz 1992 X

For observations of solar system objects an imaging polarimeter has been constructed as an auxiliary instrument for a f/15 focal reducer. With this instrument simultaneous measurement of theQ andU Stokes parameters is possible. It contains no moving parts such as a moving /2 retarder. The polarizer consists of two Wollaston prisms which are combined to form a single optical element. Their polarization angles differ by 45°. This compound polarizer is placed in the exit pupil of the afocal telescope-collimator system of the focal reducer and splits the exit pupil into halves. In this way four polarized beams with E-vector orientations 0°, 90°, 45°, and 135° emerge from the exit pupil. These are intercepted by the camera lens of the focal reducer system and imaged simultaneously on the CCD detector. With a properly designed field mask at the Cassegrain focus, the four beams are imaged without overlap.As a demonstration of the capabilities of this quadruple-beam Wollaston-prism polarimeter, we present observations of comet Tanaka-Machholz 1992 X in May 1992. The advantages, shortcomings, and possible improvements of the instrument are discussed.based on observations obtained at Hoher List Observatorypresently at Astronomical Observatory of Khar'kiv University, Sumskaya Street 35, 310022 Khar'kiv, Ukraine     

A High-Resolution Solar Telescope Using Dark-Lens Diffractive Optics

A telescope based upon dark-lens diffractive optics would be a uniquely new instrument for solar astronomy. The image formation process in such a telescope gives an intrinsically higher resolving power and a greatly reduced image intensity compared to that of refracting or reflecting optical systems of similar lens dimension. This low image intensity would be an advantage for solar observations made using a very large imaging element. After a brief overview of the history of solar instrument development, a quantitative evaluation of the dark-lens diffracting solar telescope concept is presented, showing the potential of this imaging method to meet or even to exceed the most demanding resolution goals currently being considered for future space-borne solar telescopes.     

The GSFC EUV and X-ray spectroheliograph on OSO-7

The Goddard Space Flight Center instrument carried on the pointed section of the OSO-7 satellite is described. This instrument contains: An extreme ultraviolet spectroheliograph using glancing incidence optics of Wolter's Type II to focus the Sun's light on the entrance slit of a concave grating spectrometer; an auxiliary H system; two X-ray spectroheliographs using mechanical collimators for spatial resolution and Ross filters to isolate spectral bands of interest, and a flare polarimeter operating in the 15–40 keV X-ray region. These subsystems may be operated in a number of modes which, when combined with the spacecraft modes, give the instrument great flexibility for making solar observations. Representative results from each of the subsystems are presented.     

The horizontal component of spicule motion

In movies of H spectra taken with the slit tangential to the solar limb we can observe motion of spicules both parallel to the slit and along the line of sight. We find strong evidence that, although most motion is along the axis of the spicule, some features move at right angles to their axes. Several cases were observed of features separating into two widely-split components. A power spectrum of the changes of Doppler shifts with time shows the 1/frequency characteristics of random motion.     

关于摄谱仪中畸象系统的若干讨论

本文讨论了摄谱仪中若干畸象系统,它们的作用是缩放入射狭缝的象单在高或宽的方向的尺寸,这等效于在狭缝前、后单在子午面内或弧矢面(色散方向面)内改变光束的孔径角,也等效于准直光束单在子午面或弧矢面内缩放光束宽度,在讨论中指出了准直畸象系统优于非准直畸象系统。 在着重讨论和分析准直畸象系统的不同形式时,我们提出了棱镜系统,它具有许多优点,是最为可行的方案。