A new generation of Pulkovo observatory meridian instruments and the first results of observations

The results of investigations and observations with classical meridian circle MK-200 and photographic vertical circle (PVC) after its modernization and automation are discussed. The data concerning the stability of the instrumental system and the flexure of the Pulkovo Horizontal meridian circle (HMC) are given. New work on the establishment of in axial meridian circle in Nikolaev, Ecker meridian circle and reflecting one in Pulkovo is mentioned.     

云南天文台对流星的视频观测

近20年来，随着CCD和像增强器的发展，小巧灵活的流星视频观测系统在世界上逐渐多了起来．并且，最终将可能逐步取代流星的目视观测和普通照相观测．介绍云南天文台I号流星彗星视频照相系统的研制及其初步观测结果．这一系统由容易转换的5组件构成．用于流星观测的大视场相机的视场约36度，单帧图像可观测到约6等恒星．实测的恒星星等测量精度可达约0.2等．还讨论了视频照相机比传统的感光胶卷照相的长处，以及视频照相系统的改进与发展．     

Optical Observations of Meteors

Optical observations remain the most widely used method for studying meteors, even though they are limited by daylight and weather conditions. Visual observations have been used throughout history. They lack the precision of other methods, since they rely on the judgment of observers for trajectory information. However, since no special equipment is required, visual observations are widespread, and can give valuable information on the activity profile of showers. Photographic observations are much more precise. Rotating shutters allow velocities to be determined, and networks of cameras permit the height and trajectory of a meteor to be calculated. Except for the Super-Schmidt observations at Harvard, most photographic observations record only meteors brighter than 0 magnitude. Video observations, using image intensifiers, can record much fainter meteors down to +7 magnitude. Processing is becoming very automated, so that large quantities of data can be reduced relatively easily. Most video cameras have much lower precision than photographic cameras, but new technologies are changing this. Spectral observations of meteors, using video or photographic techniques, can be used to investigate the chemistry of meteoroids, while telescopic observations allow measurements to be extended to much fainter meteors (+10 or fainter).     

A comparison of some observations of the Galilean satellites with Sampson's tables

An analysis is made of two series of photographic observations of the Galilean satellites of Jupiter. In the comparison of theory with observation, the aim of this work is to solve for systematic errors in the observations as well as those in the theory. The observations are those made by D. Pascu with the McCormick refractor during the apparition of 1967–1968 and with the 26" refractor of the U.S. Naval Observatory in 1973. Neutral density filters were used for magnitude compensation between the planet and the satellites as well as between the satellites themselves. Preliminary positions were derived by the trail/scale method using a scale value derived from scale plates taken during the observational program. The mean error of these observations is expected to be about ±0".10. The computed positions are those supplied by the Bureau des Longitudes and are based on Sampson's theory. Both intersatellary and planet-satellite positions were used in the comparison of theory with observation. The least squares adjustment included as unknowns, corrections to the longitudes, inclinations and scale for both observation types, and an additional periodic term to account for residual phase defect for the planet-satellite coordinates. The validity of the results is discussed in terms of the unknowns introduced, the correlations between them and the reduction of the residuals.     

Numerical theories of motion of Triton and Nereid

The ephemerides of satellites of major planets are needed in planning spacecraft missions both for studying the satellites themselves and for navigational support during the flights of spacecraft in the vicinity of planets. In addition, accurate numerical theories of motion of the natural satellites of major planets make it possible to increase the accuracy of the ephemerides of their central planets based on positional (photographic and CCD) observations of the satellites. Numerical theories of Neptune’s satellites, Triton and Nereid, constructed within the framework of the ERA software package developed at the Institute of Applied Astronomy of the Russian Academy of Sciences are presented.     

Astrometric studies of the series of photographic and CCD observations of the Saturnian system with the 26-inch Pulkovo refractor in 1995-2007

The results of the reduction, investigation, and comparison of the photographic observations of the major Saturnian satellites and CCD observations with an ST6 CCD camera obtained at the 264nch Pulkovo refractor in 1995–2007 are presented. A comparison of the observational results with the TASS 1.7 theory of motion of the Saturnian satellites has served as the basis for investigating and comparing the series of observations. The period-averaged (O-C) residuals and observational errors have been calculated. A comparison of the series of CCD and photographic observations has shown the same external accuracy of the observations at a higher internal accuracy of the CCD observations than that of the photographic ones. A comparison of the Pulkovo results with those of other authors has shown them to be close in accuracy. The accuracy of the theory has been estimated by comparing simultaneous (on the same night) CCD and photographic observations. The errors of the observations and the theory have been found from this comparison to be the following: 0.081“ and 0.067” for the observations and 0.077“ and 0.115” for the theory (inxandy, respectively). An analysis of the dependence of (O-C)x,y for three satellites (the sixth, seventh, and eighth) on the satellite positions in Saturn-centered orbits has revealed systemat ic deviations for the seventh satellite in both coordinates. The positions of Saturn have been determined from satellite observations without measuring its images on photographic plates with accuracies of 0.121“ and 0.105” in right ascension and declination, respectively.     

CCD suitable for double star astrometry

Summary Astrometric measurements of 18 visual double stars carried out with a CCD are given. The present observations are a test of the propriety of the CCD technique for astrometric observations of visual double stars. The duration of the observations was 75 minutes. The precision of the CCD measures corresponds the precision of the photographic method, so the advantages of CCD's are the great loss of reduction work and the corresponding time saving, inclusive shortering the observing time. Based on observations made at E.S.O., La Silla, Chile.     

The calculation of meteor motion parameters based on the single station TV observations

Recently, television observations of meteors have steadily replaced photographic observations. Television recording with short exposures is a close analog of a photographic survey with a rotary shutter in the form of a system of set time marks on the meteor track. Each meteoric event is a series of recordings of separate phases of the motion of a meteor. This allows for the use of the geometric method for the determination of the motion parameters of meteors. In this work, a critique is given regarding the concept proposed by K.P. Stanyukovich in 1932–1939, and a mathematical justification of the geometric method of the analysis of the television images of meteors is given.     

云南天文台人造卫星观测与相关应用研究

回顾了过去２０年，特别是近１０年来云南天文台人造卫星的观测与应用情况。介绍在观测仪器的研制、改进和观测方法研究以及有关激光测月资料的归算与应用方面所作过的工作。根据既有的条件，就今后若干年内可能进行的几项工作提出了粗浅的看法。     

The use of image processors for acquisition and reduction of astrometric data in real time

In Dynamical Astronomy, the data used to fit theories are positional observations. If the data are reduced using computers, the measure itself is not, and informations are lost. The classical way is to use photographic plates measured by hand. The use of automatic machine permits to save time but not to increase the amount of data.The arrival of silicium targets and CCD allows to acquire much more data directly stored on computer. We used this technique associated with array processors. So we succeeded to increase the accuracy of the data. This method was applied to the observation of the motion of some asteroids and of the Galilean satellites of Jupiter.     

Measuring fiber position errors from spectral data

Precise fiber positioning is crucial to a wide field,multi-fiber spectroscopic survey such as the Guoshoujing Telescope(the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST).Nowadays,most position error measurements are based on CCD photographic and image processing techniques.These methods only work for measuring errors orthogonal to the telescope optical axis,but there are also errors that lie parallel to the optical axis of the telescope,such as defocusing,and errors caused by the existing deviation angle between the optical axes of a fiber and the telescope.Directly measuring the two latter types of position errors is difficult for an individual fiber,especially during observations.Possible sources of fiber position errors are discussed in brief for LAMOST.By constructing a model of magnitude loss due to the fiber position error for a point source,we propose an indirect method to calculate both the total and systematic position errors for each individual fiber from spectral data.Restrictions and applications of this method are also discussed.     

天王星卫星的星历表计算

根据天王星卫星的运动理论模型（GUST86），建立了一套5颗主要卫星的星历表计算和误差分析程序。对部分高精度卫星观测位置资料进行的O－C计算和分析表明了计算程序的正确性和实用性。     

Multicolor photoelectric and photographic observations of the long-period variable Y Ori

Results of observations of the long-period variable Y Ori are presented. The photoelectric observations in UBVR were made at the 60-cm telescope of the high-altitude Maydanak station of the Tashkent Astronomical Institute during the autumn of 1989. The UBVR lightcurves as well as the variations in the color indices U-B, B-V, and V-R are presented. The photographic observations were made at the 40 Schmidt telescope of the Byurakan Observatory and at the 70-cm Maksutov telescope of the Abastumani Observatory. A nebulosity was discovered around Y Ori in red light near the brightness maximum. Such a formation is observed for the first time, not only for Y Ori but also for long-period variables in general. The obtained results are discussed in this work.Translated fromAstrofizika, Vol. 38, No. 1, pp. 5–15, January–March, 1995.     

The accuracy of observations of the Galilean satellites of Jupiter taken at the Abastumani Astrophysical Observatory of the Academy of Sciences of Georgia

The sets of photographic observations of the Galilean satellites of Jupiter taken at the Abastumani Astrophysical Observatory of the Academy of Sciences of Georgia are analyzed here. Positional observations of the system of Jupiter were made in the period from 1985 to 1994 with the use of the double Zeiss astrograph in order to determine the exact coordinates of Jupiter and its satellites. The accurate positions of the satellites and Jupiter itself, as well as their stellar (equatorial) coordinates relative to the stars of the currently available catalogs and the relative ??satellite ?? satellite?? coordinates were obtained from the observations. From the comparison of the observation results with the modern theories of motion of satellites, the accuracy in determining the positions of the satellites and Jupiter was analyzed. The results of observations are presented in the Pulkovo database of observations of Solar System bodies that is accessible to users at http://www.puldb.ru.     

On the Origin of the 1999 Leonid Storm as Deduced from Photographic Observations

Photographic multi-station observations of 18 Leonid meteorsobtained by the Spanish Photographic Meteor Network are presented. For each meteoroidthe radiant position, trajectory data and orbital parameters are discussed and compared totheoretical radiant positions and orbital elements of particles ejected from 55P/Tempel–Tuttle in 1899.We discuss the role of mean velocity imprecision in the dispersion of some orbital parameters,specially the semimajor axis. Finally, by applying the dust trail theory we have adjusted the1999 Leonidstorm orbits to a defined semimajor axis value to test the quality of photographic observations.     

Astrometric studies of the results of a new reduction of old photographic observations of the Saturnian System based on the comparison with the modern theories of satellite motion

The paper shows the possibility of increasing the accuracy of the results of photographic observations of Saturn and its moons made in the 1970s and reduced using the old reference star catalogues and semiautomatic measurements. New celestial coordinates of the moons (from the third to the eighth), “satellite minus satellite” relative moon coordinates, and Saturn coordinates by positions of satellites are obtained without measuring its images. The results are stored in the Pulkovo Observatory database on the Solar System bodies and are available online at www.puldb.ru. The efficiency of the reduction method based on digitizing of astronegatives using 21 Mpx Canon digital camera and IZMCCD software is shown. The comparison of new results of old observations with the latest theories of moon motion has revealed a significant increase in satellite positioning accuracy. The investigation of the differences (O–C) of celestial coordinates from satellite positions in their apparent Saturn-centric orbits has revealed a noticeable motion of the differences (O–C) in right ascension depending on their distances from Saturn for all moons.     

A long-term photometric study of the pre-main-sequence star V 350 Cep

Results from photographic and CCD photometric observations of the pre-main sequence star V 350 Cep are presented. A continued gradual rise of brightness resembling the light curves of the FUOR type stars is observed. A search in the WFPDB was made to find old photographic observations of V 350 Cep.     

The Lembang's Photographic Observations on Sirius

1　ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｒｉｕｓ (α2 0 0 0 =6 ｈ45 ｍ2 ,δ2 0 0 0 =- 1 6°41′) ,ｔｈｅｂｒｉｇｈｔｅｓｔｓｔａｒｉｎｔｈｅｓｋｙ ,ｉｓａｄｏｕｂｌｅｓｔａｒｓｙｓｔｅｍｗｉｔｈｌａｒｇｅｍａｇｎｉｔｕｄｅｄｉｆｆｅｒｅｎｃｅｂｅｔｗｅｅｎｔｈｅｔｗｏｃｏｍｐｏｎｅｎｔｓ (Ｖ =- 1 5 8ｆｏｒｔｈｅｂｒｉｇｈｔｅｒｓｔａｒａｎｄ 8 44ｆｏｒｔｈｅｓｅｃｏｎｄａｒｙ) .Ｔｈｉｓｙｉｅｌｄｓｖｉｓｕａｌｏｂｓｅｒｖａｔｉｏｎｓｔｏｂｅｍａｄｅｏｎｌｙｗｈｅｎｔｈｅｓｅｐａｒａｔｉｏｎｓａｒｅｌａ…     

Results of astrometric observations of Jupiter’s Galilean satellites at the Pulkovo Observatory from 1986 to 2005

The results of photographic observations of Jupiter’s Galilean satellites made with the 26-inch refractor at the Pulkovo Observatory from 1986 to 2005 are given. Satellite coordinates with respect to Jupiter and the mutual distances between the satellites have been determined. A scale-trale technique that does not require reference stars for the astrometric reduction of measurements has been used. The effect of the Jupiter phase has been taken into account in the jovicentric coordinates. The observation results have been compared with a modern theory of the Galilean satellites’ motions. Systematic observation errors depending on the observation technique have been studied. The intrinsic observation accuracy in the random quotient is characterized by the values 0.041″ over X and Y. The external accuracy of the relative Galilean satellite coordinates determined by comparing the observations with modern ephemerides turned out to be equal to 0.165″, 0.213″ for the Jovicentric coordinates and 0.134″, 0.170″ for the “satellite-satellite” coordinates. The highest accuracy of the relative satellite coordinates is reached at small distances between the satellites which are less than 100″: the corresponding mean-square errors of one observation are equal in to the external convergence to 0.050″, 0.070″. The results of photographic observations have been compared with the first CCD observations of the Jupiter satellites made in 2004 with the 26-inch refractor.