Möglichkeiten der photometrischen Untersuchung von Kugelhaufen mittels photographischer Äquidensiten

A method of estimating the surface-brightness of globular cluster with equidensity curves is described. (Russian abstract)     

Zur Aufhellung des Nachthimmels über dem KARL-SCHWARZSCHILD-Observatorium Tautenburg

The measurements of the sky brightness show during a partial cut off of the outdoor lighting at Jena a decreasing of the sky brightness at Tautenburg by 20%.     

Photographic Photometry of Objects near 5C1 Radio Sources

Photographic photometry and objective prism spectroscopy has been performed for most of the objects near 5C1 radio sources brighter than 19^m.6 discussed by NOTNI and FRöHLICH (1975). Updated samples of identification candidates are presented. The mean reliability of the identifications is better than 90% for blue starlike or concentrated objects and 67% for galaxies. In addition, a few bright galactic stars seem to occur among the radio sources.     

Application of an adaptive filtering technique to surface photometry of galaxies. I. The method tested on NGC 3379

This study reports on the results of the application of an adaptive filtering technique to the two-dimensional photometric mapping of galaxies. For this test we used the elliptical galaxy NGC 3379, which is a luminosity standard. Our plate material (B-band), obtained with the Tautenburg Schmidt telescope, was digitized with the Babelsberg microdensitometer and with the ESO PDS. The 2-D scans were reduced according to the Babelsberg Image Processing Systems, whose key feature is an adaptive filter called ‘H-Transform’. By comparing our results (E-W light profile and isophotal parameters) to the most recent studies of NGC 3379 (DE VAUCOULEURS and CAPACCIOLI 1979, and NIETO and VIDAL 1984), we found no systematic errors in the photometric calibration and in the reduction procedure, with typical mean residuals from the other studies not larger than ±0.05 B-mag up to a threshold of 1% of the night sky level on each plate. We also re-confirmed the geometrical properties of the galaxy. The new filtering technique proved quite efficient in reducing the noise, with negligible effects on the photometric and geometric characteristics of the star-like sources.     

Photometrische Kalibrierung von Schmidtspiegelaufnahmen durch ein bildteilendes Hilfsprisma

Plates of the Tautenburg Schmidt can be calibrated with the aid of a beam-splitting prisma only if Schraffierkassette plates are used. The effects of image structure, scintillation and intermittence on in-focus images are different for the main component and the prismatic companion. Therefore, such plates cannot be used to set up a photometric scale.     

Investigation of clusters of galaxies. III. An U band photometry in the central part of the Coma cluster

A photographic photometry in U was performed for 288 galaxies in the central field of the Coma cluster of galaxies.     

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.     

Investigations of clusters of galaxies near the North Galactic Pole

The number-density distribution of several clusters of galaxies was derived by counting galaxies on B and R plates of the 2-m Schmidt telescope of the Karl-Schwarzschild-Observatory Tautenburg.     

Investigation of clusters of galaxies. I. Explanation of photometric scale of errors by light diffusion in a photographic emulsion

A photographic photometry in B and V was performed for 326 galaxies in the central field of the Coma cluster. We found an explanation (diffusion of light in the emulsion according to an earlier investigation of ZIENER ) for the systematic deviation between the results from ROOD and BAUM and from GODWIN and PEACH in the V pass band. We conclude that the photometry of ROOD and BAUM is true. Diffusion also can explane the results of FONG , GODWIN , and METCALFE .     

Investigation of clusters of galaxies II. A two colour photometry for the cluster Abell 1795

Eine photographische Photometrie in B and V wurde für den cD-Haufen A 1795 durchgeführt. Dieser Haufen liegt in der Nähe des galaktischen Nordpols. Unser Katalog enthält 721 Galaxien in einem Gebiet von 1.6 ° um das Haufenzentrum.