First astronomical observatory in Lviv

This historical essay highlights the state of the art for astronomical researches in Lviv dating back to the end of 18th century, the information is given concerning earliest documentary substantiated astronomical observations held in Lviv. The circumstances of foundation and building astronomical Observatory at Jesuit College (University) are depicted, the foundation date is determined by archival materials, it is 15 of May, 1771. We have investigated the role played by Observatory during the incorporation of Galicia (Halychyna) into Austro-Hungarian empire. The biographical data are collected and arranged concerning prominent astronomers and engineers of those times, the lives of which were somehow connected to Lviv Observatory.     

The IPS work in Beijing astronomical observatory

This article describes the IPS work in the Beijing astronomical observatory including the hardware and software of the instrument and some theoretical research.The project is supported by the China National Nature Science Fundation under the program 49391400     

Ultraviolet observations of Mars made by the orbiting astronomical observatory

Ultraviolet albedos of Mars in the region γγ2000–3600 Å are discussed. When the reflectivity due to the known amount of CO₂ on Mars is accounted for, the remaining reflectivity may be used to set an upper limit for the surface albedo. The result disagrees qualitatively with published ultraviolet reflectivities of limonite and carbon suboxide. An alternate interpretation of the observations leads to the conclusion that CO₂ comprises at least 60% of the molecular atmosphere of Mars, assuming the remainder to be argon. A comparison of the OAO results with 1969 Mariner ultraviolet data reveals some important areas of conflict.Attempts to detect Mars at wavelengths less than γ2000 Å were unsuccessful, with only very high upper limits being set.     

The astrolabe catalogue (ACPI) of the Peking astronomical observatory

Using the results of our latitude and time programs obtained with the impersonal astrolabe (OPL No. 30) of the Peking Observatory, we have calculated the corrections to individual star positions and the systematic corrections Δα_δ and Δδ_δ to catalogue positions.     

Statistical analysis of the results of champ occultation data processing at Shanghai astronomical observatory

With the development of the CPS (Global Positioning System) it has become possible to retrieve accurate profiles of atmospheric temperature, pressure and moisture from CPS occultation data. Using the inversion module developed in Shanghai Astronomical Observatory, (SHAG), we obtained atmospheric profiles from more than 2700 CHAMP occultation events observed in the period 2002 Aug. 1–17. The retrieved profiles are compared with the data of the European Center for Medium-range Weather Forecasts (ECMWF), and their errors are analyzed. An optimal method of statistical analysis is proposed and applied. The statistical results show that GPS occultation data may contribute valuably to numerical weather forecast and long-term monitoring of the earth's climate.     

Some new astronomical facilities in China

For the 1990's, plans for some astronomical facilities and related researchers are being carried out in China. In this report we describe in some details the plans of radio astronomical facilities, 150/220 cm Schmidt telescope, and experiments on porcelain mirror material.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

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.     

Astronomical research activities with the 74 inch telescope at Kottamia observatory

Two topics of research, namely extragalactic and variable star studies represent the main attitudes of astronomical work at the Helwan Observatory.The 74 inch telescope at Kottamia (476 m, 2^h.12, 29^°.93 N) some 60 km to the east of Cairo is the main instrument. Some other auxiliary equipment (Cassegrain and echelle spectrographs, Westinghouse and Japanese cameras and photoelectric photometer) can be attached at both Cassegrain and Newtonian foci.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

A study of the astrometric motion of Barnard's star

The Astrometric technique is unique in that it allows us to do a systematic search of each nearby star to determine whether or not it is the primary star of a planetary system. Both positive and negative results may be expressed with a well defined statistical certainty. Perhaps the best known astrometric study is that of Barnard's star by van de Kamp (1963). That detection was later discounted by Gatewood and Eichhorn (1973) but neither study attempted to specify what types (in mass and orbital period) of planets do not orbit Barnard's star. In the following pages we will relate the results of an ongoing study of that object, qualifying what types of bodies are unlikely to orbit Barnard's star, and showing what we believe to be the first step by step illustration of the various astrometric motions that must be analyzed in this study.     

Radio-silent isolated neutron stars as a new astronomical reality

Summary. As of today, seven X-ray sources have been tentatively identified as radio-quiet, isolated neutron stars. The family appears to be a rapidly growing one, although not all the objects have been identified with the same degree of certainty. The most convincing example of radio quiet pulsar is certainly Geminga, the neutron star nature of which, proposed in 1983 on the basis of its similarity with the Vela pulsar, has been firmly established with the discovery of its X and pulsation. Four more neutron star candidates, originally found in the Einstein data, have been confirmed by ROSAT, which has added to the list two more entries. All this is not the result of an unbiased search. The seven sources were not selected at random: four are inside supernova remnants, an obvious place to search for isolated neutron stars, while the remaining three were singled out because of some peculiarity. Intense -ray emission in the case of Geminga, very high X-ray counting rate for RXJ185635-3754, or being the brightest unidentified source in the Einstein medium sensitivity survey, MS 0317-6647. In spite of the limited number of objects and of the observational biases, these seven radio quiet neutron star candidates add valuable pieces of information to the observational panorama of known pulsars. Their properties, inferred from the X-ray emission, offer a coherent picture, pointing towards thermally emitting, cooling neutron stars. Received: April 1, 1996     

A new spectrum analyzer for radio astronomical studies with the radio telescope RATAN-600

The spectral measuring facility with a new Fourier analyzer for use with the radio telescope RATAN-600 is described and its experimental data are reported.     

A comparison of the measuring machines APM and MAMA for astrometric application

Measurements of two Tautenburg plates were used for a comparison of the astrometric accuracy of the automatic measuring machines PAM and MAMA. From plate-to plate solutions a positional accuracy of about 1 μm was achieved for stars with 7 < B < 17 for MAMA and with 11 < B < 17 for APM measurements. A rapid decrease in positional accuracy of fainter stars is caused rather by random effects of the photographic emulsion. A magnitude equation between the plates was obtained to be less than 1 μm over the whole magnitude range. Systematic errors with a small period of 2 cm in the APM measurements as well as a non-orthogonality and systematic differences between the MAMA and APM coordinate grids were found. A procedure of classifying all real objects measured into stars, galaxies and merged objets is presented for the MAMA measurements and the results are compared with the routine APM classification. Except for merged objects the MAMA and APM classification show a very good agreement for stars brighter than B = 18.5.     

A comparison of astrometric measurement techniques as applied to minor planets

Differential and absolute minor planet positions previously applied to the study of a Fundamental Reference System have had accuracies of the order of ±.2. Relative positions have been obtained to much higher accuracy, but that accuracy has not been applied directly to the formation of a celestial coordinate system. The regular motions of minor planets along long arcs in the sky are more accurately known than any single observed position. Thus, the dynamics of minor planets, coupled with new techniques of observation and reduction, will bring an independent component to bear on the problem of testing the Fundamental Reference System. Preliminary results based on measurements of Hypatia (238) are presented.Proceedings of the Conference on Analytical Methods and Ephemerides: Theory and Observations of the Moon and Planets. Facultés universitaires Notre Dame de la Paix, Namur, Belgium, 28–31 July, 1980.     

Digitizer of astronomical plates at Shanghai Astronomical Observatory and its performance test

Before CCD detectors were widely employed in observational astronomy, the main method of detection was the use of glass astrophotographic plates. Astronomical plates have been used to record information on the position and activity of celestial bodies for more than 100 years. There are about30 000 astronomical plates in China, and the digitization of astronomical plates is of great significance for permanent preservation and to make full use of these valuable observation data. A digitizer with high precision and high measuring speed is a key piece of equipment for carrying out the task of digitizing these astronomical plates. A digitizer for glass astrophotographic plates was developed jointly by Shanghai Astronomical Observatory and Nishimura Co., Ltd of Japan. The digitizer's hardware was manufactured by Nishimura Co., Ltd, and the performance test, error corrections as well as image processing of the digitizer were carried out by Shanghai Astronomical Observatory. The main structure and working mode of the digitizer are introduced in this paper. A performance test shows that brightness uniformity of illumination within the measuring area is better than 0.15%, the repeatability of digitized positions is better than 0.2 μm and the repeatability of digitized brightness is better than 0.01 instrumental magnitude. The systematic factors affecting digitized positions, such as lens distortion, the actual optical resolution, non-linearity of guide rails, non-uniformity of linear motors in the mobile platform,deviation of the image mosaic, and non-orthogonality between the direction of scanning and camera linear array, are calibrated and evaluated. Based on an astronomical plate with a size of 300 mm × 300 mm,which was digitized at different angles, the conversion residuals of positions of common stars on different images were investigated. The results show that the standard deviations of the residuals are better than 0.9 μm and the residual distribution is almost random, which demonstrates the digitizer has a higher precision for digitization.