Comet Hale-Bopp (C/1995 O1): UVSTAR-FUV Spectroscopy from the Space Shuttle

We report here on unique post-perihelion (2.3 AU) measurements of Comet Hale-Bopp in the FUV-range (950–1250 Å) by means of the UVSTAR spectrometer from the space shuttle with the main purpose of searching for argon and other FUV emitters. New methods for separating the strong airglow emission at shuttle altitudes are here discussed in detail. Due to our low resolution (15 Å) and S/N ratio the possible rocket-borne detection of argon near perihelion (0.9 AU) could not be confirmed. New species as N₂ are suspected but difficult to separate from the strong airglow emission at shuttle altitudes. From the Lyα brightness (1.30± 0.08 kRy) a water production rate Q = 5.9 ± 0.4 × 10²⁹ molecules s^?1 could be derived and compared with other post-perihelion observations.     

Prof. Dr. Eduard Rübel

Ohne Zusammenfassung     

Die Tektonik der Eisenspatgänge von Grube “Georg” im Westerwald

Zusammenfassung Die Spateisensteingänge von Grube Georg wurden in einem Spätstadium der Faltung gebildet. Es sind Diagonalscherflächen, die im Bereich einer Achsenflexur aufrissen und an denen Abschiebungen stattfanden. Ihnen entsprechen weitere, nicht vererzte Abschiebungen.Nach der Gangbildung, aber noch während der Faltung, entstanden parallel den Faltenachsen jüngere Scherflächen (vorwiegend Überschiebungen).Jünger als die Faltenbildung sind gangversetzende, NE-streichende Seitenverschiebungen.     

Mean bulk densities of samples of dry atmospheric aerosol particles: A summary of measured data

Mean bulk densities of various samples of dry atmospheric aerosol particles sampled at different sites and during different seasons and weather situations range between 1.8 and more than 3 gm cm³.     

Comment on the feasibility of using a crystalline detector for gamma-ray astronomy

We discuss the feasibility of using the coherent electric field in crystal as a means for gamma-ray astronomy. At 100 GeV, pair production is enhanced along the crystalline axis. However, the expected celestial gamma-ray flux at this energy is insufficient for this technique to be viable with a conventional-size satellite detector.     

Optical polarization of the Crab pulsar: precision measurements and comparison to the radio emission

The linear polarization of the Crab pulsar and its close environment was derived from observations with the high-speed photopolarimeter Optical Pulsar TIMing Analyser at the 2.56-m Nordic Optical Telescope in the optical spectral range (400–750 nm). Time resolution as short as 11 μs, which corresponds to a phase interval of 1/3000 of the pulsar rotation, and high statistics allow the derivation of polarization details never achieved before. The degree of optical polarization and the position angle correlate in surprising details with the light curves at optical wavelengths and at radio frequencies of 610 and 1400 MHz. Our observations show that there exists a subtle connection between presumed non-coherent (optical) and coherent (radio) emissions. This finding supports previously detected correlations between the optical intensity of the Crab and the occurrence of giant radio pulses. Interpretation of our observations requires more elaborate theoretical models than those currently available in the literature.