Astrometrische Verwendung der zweiten kurzen Exposition auf Tautenburger Pilotprogrammplatten

To overcome a possible magnitude equation the Tautenburg Schmidt plates of the Lohrmann programme were taken with a long 20-minute exposure (System A) and a short 20-second exposure (System C) displaced about 0·5 minute of arc in declination from the long exposure. The distance between the two images in dependence on the magnitude of a star and its position on the plate was analysed. The transformation of coordinates from system C to A can be performed by using first order polynomials. No higher order terms were found to be necessary. The coefficients of the polynomials can not be assumed as constant for all plates but must be computed from least squares solutions involving a sufficient number of stars on each plate. For three of four plates investigated significant orthogonal linear terms were detected.     

Verwendbarkeit des Prismas auf der Korrektionsplatte des Tautenburger Schmidt-Spiegels bei Positionsbestimmungen

To overcome a possible magnitude equation a weakly refracting prism fitted on the correcting plate of the Tautenburg Schmidt telescope was used, forming a secondary image of every object 3.8 mag weaker than the primary one. Because the distances between these two images are not constant, a polynomial was searched which could reflect these variation in dependence on the magnitude of a star and its position on the plate. For each of the 11 plates tested we have got another polynomial, therefore this way to tide over large magnitude differences is unefficient for astrometric investigations.     

An astrometric model for Tautenburg Schmidt plates

The major principles of establishing a statistical model for plates of the Tautenburg Schmidt telescope (134/200/400) are described. The model is intended to be used for the Monte Carlo simulation of the determination of coordinates and proper motions. It has been tested with orthogonal polynomials by determining positions of stars. Under certain conditions linear equations are sufficient for the reduction of measured to standard coordinates when using the AGK3 as the reference system.     

A Programme to derive from terrestrial observations the rotation of the HIPPARCOS system with reference to the inertial system

The connection of the HIPPARCOS system with a quasi-inertial system can be reached by transforming the HIPPARCOS proper motions to absolute proper motions. The Tautenburg Schmidt telescope provides such proper motions with respect to extragalactic objects with an accuracy of 0″.6/100a. The telescope as well as the measuring and reduction technique are described. The accuracy of the link of the HIPPARCOS system to extragalactic objects depends on the accuracy of the transformation matrix which represents the time-depending part of the rotation matrix to be applied to the whole HIPPARCOS catalogue. To obtain a reliable estimate for the error of transformation we used the error propagation law. An accuracy of 0″.12/100a for the transformation can be achieved with six Tautenburg fields.     

Beobachtungen Kleiner Planeten. XV.

A summary is given about the Minor Planet survey performed in 1994 on Tautenburg Schmidt plates. 321 asteroids were observed and 1171 positions are calculated for them. These are 200 asteroids with provisional designations (102 of them have new designations) and 121 numbered objects. Tautenburg observations could give a tribute to 73 planets numbered in the period of this report. Fourteen Tautenburg asteroids have been numbered.     

Beobachtungen Kleiner Planeten. IX

A summary is given about the minor planet survey performed in 1988 on Tautenburg Schmidt plates. There were discovered 386 asteroids and 1218 positions were calculated for them. These are 87 numbered objects and 299 asteroids with provisional designations, 252 of them have new designations. Tautenburg observations contributed to 40 planets numbered in the period of this report, including eight discovered in Tautenburg.     

Beobachtungen Kleiner Planeten. XIV

A summary is given about the Minor Planet survey performed in 1993 on Tautenburg Schmidt plates. 392 asteroids were observed and 1462 positions are calculated for them. These are 297 asteroids with provisional designations (217 of them have new designations) and 95 numbered objects. Ten new designations originate from the KSO-ARI-Survey IV. Tautenburg observations could give a tribute to 50 planets numbered in the period of this report. Six Tautenburg asteroids have been numbered (Tab. 3).     

Beobachtungen Kleiner Planeten. III

A summary is given about the Minor Planet survey performed in 1982 on Tautenburg Schmidt plates. We discovered 229 planets and calculated 643 positions for them. Tautenburg observations have given a tribute to ten planets numbered in 1982. Planet (2424) discovered by us has received the name Tautenburg.     

Beobachtungen Kleiner Planeten. VII

A summary is given about the Minor Planet survey performed in 1986 on Tautenburg Schmidt plates. There were discovered 129 asteroids and calculated 312 positions for them. These are 29 numbered objects and 100 asteroids with provisional designations, six of them have no new designations. Tautenburg observations could give a tribute to five planets numbered in the period of this report, including the asteroid 1981 VW1 discovered in Tautenburg which received the number (3499) and the name Hoppe.     

Beobachtungen Kleiner Planeten. VI.

A summary is given about the Minor Planet survey performed in 1985 on Tautenburg Schmidt plates. There were discovered 95 asteroids and calculated 168 positions for them. These are 20 numbered objects and 75 asteroids with provisional designations, two of them have no new designation. Tautenburg observations could give a tribute to twelve planets numbered in the period of this report. Two asteroids discovered in Tautenburg have received numbers and names: (3245) Jensch = 1973 UL5 and (3338) Richter = 1973 UX5.     

Beobachtungen Kleiner Planeten. V

A summary is given about the Minor Planet survey performed in 1984 on Tautenburg Schmidt plates. We discovered 84 planets and calculated 205 positions for them. Among them are 17 numbered planets, 16 already earlier observed and 51 new planets with provisional designations. Tautenburg observations could give a tribute to seven planets numbered in the period of this report. The planet 1964 EC discovered in Tautenburg has received the permanent number (3181). In honor of Dr. PAUL AHNERT (^*22. 11. 1897) this planet obtained the name Ahnert.     

Beobachtungen Kleiner Planeten. IV

A summary is given about the Minor Planet survey performed in 1983 on Tautenburg Schmidt plates. We discovered 147 planets and calculated 272 positions for them. Tautenburg observations could give a tribute to fourteen planets numbered in the period of this report. The planet 1981 VL 2 discovered in Tautenburg has received the permanent number (2861). In honor of Prof. HERMANN LAMBRECHT († 4. 6. 1983) this planet obtained the name Lambrecht.     

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.     

Berücksichtigung inhomogenen Hintergrundes bei der Irisblendenphotometrie

Different methods for correcting non-uniform background fog levels in iris diaphragm photometry are compared. For this purpose data measured by SCHAEFER (1979, 1981) and also our own measurements on Tautenburg plates are used. Finally some rules for measuring plates with non-uniform background are given.     

Semi-automated extraction of digital objective prism spectra

We describe a method for the extraction of spectra from high-dispersion objective prism plates. Our method is a catalogue-driven plate solution approach, making use of the right ascension and declination coordinates for the target objects. In contrast to existing methods of photographic plate reduction, we digitize the entire plate and extract spectra off-line. This approach has the advantages that it can be applied to CCD objective prism images and spectra can be re-extracted (or additional spectra extracted) without having to re-scan the plate. After a brief initial interactive period, the subsequent reduction procedure is completely automatic, resulting in fully reduced, wavelength-justified spectra. We also discuss a method of removing stellar continua using a combination of non-linear filtering algorithms.   The method described is used to extract over 12 000 spectra from a set of 92 objective prism plates. These spectra are used in an associated project to develop automated spectral classifiers based on neural networks.     

Selection,Statistics and Photometry of Compact Galaxies with Different Instrumental Equipment. Part I

On plates taken with 2 different photographic telescopes compact galaxies in 3 fields near M₃ and M₉₂ were selected. The integral magnitudes and maximum angular diameters of the compacts were determined. The RITCHEY -CHRéTIEN telescope of the FIGL Observatory for Astrophysics (FOA) with a focal ratio of 1:8.3 has a scale of 1 mm = 16.3, while the Tautenburg SCHMIDT with 1:3.2 has a scale of 1 mm ≌ 52°. From the selection statistics for both telescopes results nearly the same number of objects (50) up to 18^m.5 in V in a field of 1.5□°.60% of these objects are identical. An integral photometry on B plates of the same limiting magnitude from both telescopes leads to nearly the same brightness of objects, while they are o^m.5 fainter on FOA V plates. Because of its smaller focal ratio this telescope does not record the halo parts of the compacts. This is clearly demonstrated by the maximum equidensitometric diameters which on FAO plates are on the average only half of those determined on Tautenburg plates. A diameter magnitude diagram is shown.     

On the Real Number of Objects in the Tautenburg Catalogues of Blue Objects Suspected as Quasistellar (QSO)

The results of the U, B, V photometries of W. BRONKALLA and N. RICHTER near the north galactic pole are discussed. In these photometries which have been carried out on the same Tautenburg Schmidt plates the share of blue objects suspected as quasistellar (QSO) has been determined by total photometry of all starlike objects in selected partly overlapping test fields. The results of both photometries agree very well. The position of the blue objects of the Tautenburg catalogues and BRONKALLA's photometry in the two-colour diagram is compared with the two-colour diagram of QSO's published by C. BARBIERI and M. CAPPACIOLI . In both cases 65 per cent of the objects are placed on the right-hand side and 35 per cent on the left-hand side (region of white dwarfs) of the black-body line. Therefore, it is no longer admissible to qualify in a photometric statistics of blue objects all those objects as white dwarfs which are situated on the left-hand side of the black-body line in the two-colour plot. This result is confirmed by the discussion of the number-magnitude relation of these objects. Clustering of blue objects and their connection with clusters of galaxies are discussed. Using results from A. SANDAGE and E. M. BURBIDGE and our own results one can conclude that more than 60 per cent of Tautenburg blue objects must be QSO's. For further spectroscopic and proper motion investigations it is proposed to prefer the objects placed on the left-hand side of the black-body line in order to obtain the real share of white dwarfs in this group of objects suspected to be quasistellar.     

Beobachtungen Kleiner Planeten. XIII

Es wird eine Übersicht gegeben über die im Jahr 1992 auf Tautenburger Schmidtplatten gefundenen Kleinen Planeten. Es wurden 518 Objekte beobachtet und für diese 2396 Positionen gerechnet. Es handelt sich um 408 Planetoiden mit provisorischer Bezeichnung, unter denen 274 neu vergebene Bezeichnungen sind, sowie um 110 numerierte Objekte. Für 172 Tautenburger Objekte wurden Bahnen aus einer Opposition gerechnet. Für 55 im Berichtszeitraum numerierte Planeten haben Tautenburger Positionen einen Beitrag geleistet. Acht Tautenburger Planetoiden wurden numeriert (Tab. 3). A summary is given about the Minor Planet survey performed in 1992 on Tautenburg Schmidt plates. 518 asteroids were observed and 2396 positions are calculated for them. These are 408 asteroids with provisional designations (274 of them have new designations) and 110 numbered objects. One-opposition orbits have been computed for 172 Tautenburg asteroids. Tautenburg observations could give a contribution to 55 planets numbered in the period of this report. Eight Tautenburg asteroids have been numbered (Tab. 3).     

Beobachtungen Kleiner Planeten. II

Here is a summary about the Minor Planet survey performed in 1981 on Tautenburg Schmidt plates. We discovered 294 planets and calculated 614 positions for them.