Über schnelle Änderungen der magnetischen Feldstärke von Sonnenflecken

The results from hourly measurements of the magnetic field strengths of several main spots in three selected spot groups within the years 1968/69 are given in graphs. The values of the field strength used in the graphs are mean values out of three spectrograms taken immediately one after another. The mean error of a mean value is ±85 Gauss. Besides a general tendency in the daily course of the field strength the graphs are showing rapid variations up to 500 Gauss within a few hours. In contrast to these variations which are probably real, the frequent short time variations indicated cannot be regarded as certain. In addition to the observations of the field strength the development of the spot groups is described, and informations on the flare-activity are given.     

Sternentwicklung auf dem Horizontalast und Zustandsgrößen von RR-Lyrae-Sternen in Kugelhaufen verschiedenen Alters

The behaviour of the masses, the luminosities, the radii, and the colours of the RR Lyrae stars situated in 7 globular, clusters is investigated in dependence upon the clusters' age. The ages were determined according to a method by SANDAGE ; the determination of the masses is based on relations derived by BAKER . In is found that, with increasing age of the clusters, the mean values of masses, luminosities, and radii of the RR Lyrae variables decrease whereas the periods become larger and the centres of the RR Lyrae gaps bluer. The masses tend (with large scattering) to values smaller than one solar mass and support in this respect the models by CHRISTY and by FAULKNER and IBEN .     

Untersuchung von Spektrenplatten (ORWO-Emulsion ZU 21) hinsichtlich der Lageänderung von Linien bei bestimmten Trocknungsbedingungen

Relatively large displacements are found on plates used for work in stellar spectroscopy. The maximum amount of the displacements in the emulsion are local in the order of 16 m̈m. Obviously these effects are independent on the drying process. Correlations of large local displacements can not be found between the regarded test plates.     

Beobachtungsmöglichkeiten zur Linschen Dichtewellentheorie (Mitteilungen der Universitäts-Sternwarte zu Jena Nr. 130)

After summarizing the most important effects predicted by the density-wave theory the possibilities of observing these effects are discussed. The observation of structural effects in our own Galaxy is very difficult, mainly because of the inaccurate distances available. Only rough structures can be obtained. That is also true for observations near such points, in which the line of sight is tangential to the spiral arms. Observations of kinematical effects in our own Galaxy and of structural effects (kinematical ones are not discussed) in extragalactic spiral systems should yield some useful results.     

MAXWELLs Äthertheorien

The present paper is devoted to MAXWELL 's most peculiar finding of his celebrated theory of electrodynamics. We explain carefully the essential ideas of MAXWELL 's works from 1855 and 1861/62 in a modern style of reasoning and the nomenclature used nowadays. Quotations refer to ”︁The Scientific Papers of J. C. MAXWELL ” (1890).     

Zur dynamischen Äquivalenz der post-NEWTONSCHEN Näherung für die Planetentheorie in der allgemeinen Relativitätstheorie und in der trägheitsfreien Mechanik mit RIEMANNSchem Gravitationspotential

Proof of the dynamical equivalence of the post-NEWTONian approximations for the LAGRANGAIN representations of planetary motions according to GRT and according to our “RIEMANNian dynamics with MACH EINSTEIN doctrine”. Finally, we discuss the equivalence problem for general post-NEWTONian LAGRANGians of the one-body Problem in celestical mechanics.     

Über die Möglichkeit,die Temperaturverteilung in Sonnenflecken durch einen anisotropen Wärmetransport zu erklären

Numerical solutions of a heat conduction problem in an anisotropic medium are used for a discussion of the possibility to explain the temperature distribution in sunspots and their environment. The anisotropy is assumed being due to the strong magnetic field in sunspots and the region below. This magnetic field forces the convection to take an anisotropic structure (two-dimensional turbulence) and thus the region gets anisotropic conduction properties, on the average. The discussion shows that the observed temperature profiles can be explained in case the depth of the region of anisotropy is about as large as the diameter of the spot or larger.     

Axtell and Allende: A Mössbauer spectroscopic study

Abstract— Mössbauer spectra showed the CV3 oxidized subgroup meteorites Allende and Axtell to be similar in olivine content and in a surprising lack of pronounced magnetic components, but different in Fe³⁺ phases. One atypical Allende sample showed an 8% area under the curve for magnetite, which is still less than a reported value for a CV3 reduced subgroup member. Allende's unusual Fe³⁺ spectral region distinguishes it from most other stony meteorites and is difficult to fit to known mineral parameters.     

Zur Methodik der Bestimmung von Entdeckungswahrscheinlichkeiten veränderlicher Sterne

The Bernoullian statistics give for rare types of variable stars only inaccurate results concerning the probability of discovery p. In these cases p may be reasonably calculated by means of the „Quality Function”︁ Q(Δm, m), defined by Borgman. Q(Δm, m) is the probability of the discovery of a magnitude difference Δm near the apparent magnitude m. Three methods are discussed which allow to find Q(Δm, m). An application to the Sonneberg material shows, as expected, that Q(Δm, m) will become smaller with Δm decreasing and m increasing. Moreover the psychologically interesting fact, already supposed by Borgman, is confirmed that even well-trained observers will overlook about 10% of all large magnitude differences < 1 mag in using the blink-, stereo- or electronic scanning method for the discovery of variable stars.     

Neue Bestimmungen der Präzession nach dem Prinzip der Maximalmenge von Sternen ohne meßbare Eigenbewegung

The principle of the maximum set of stars without proper motions (μ = 0) requires that the corrections of the precession be specified so that the number of the stars “without proper motion” (practically μ < 0″.10) becomes a maximum. These stars are named the “Träger” (carriers) of the non-rotating coordinate system. The method avoids any hypothesis about the distribution of the proper motions and hence does not use the method of least squares. The procedure algorithmized in the FORTRAN language and computed on a UNIVAC 1108 is based on the geometric means of a regular sequence of numbers of stars within concentric circles around the position μ = 0 with growing radius in a rightangle coordinate system with the axes μαcos δ and μδ. The main concept is the “zero-point density” D in the defining equation (13). The inequality (15) is the main relation of the method, where r is the radius of a circle-neighbourhood of the position μ = 0. The main part of the procedure in praxi and the algorithm are described in section 5. In sections 6, 7 and 8 the method is applied to the proper motions of the catalogue FK₄, then to the proper motions of the catalogue N₃₀ and finally to a third catalogue, which consists of the proper motions of N₃₀ reduced to the system of FK₄ (N₃₀ → FK₄). The main result lies in table 4 of section 9. With regard to the accuracy as well as to the number of the “Träger” (carriers) of the coordinate system free of rotation the results from (N₃₀ → FK₄) have the following implications: the corrections of lunisolar precession Δp₁ = +0″.97 ± 0″.04 per century; the correction of the motion of equinox Δp₂ = Δλ + Δc = +1″.10 ± 0″.04 per century. For the motion of equinox Δp₂ = Δλ + Δc = +1″.10 ± 0″.04 per century. For the purpose of investigations of motions of stars these corrections correspond to the corrections (21) of the proper motions of N₃₀ → FK₄. The new method has the advantage also, that fewer than half of the stars of a catalogue can influence the result (table 6).     

Zur Entwicklung von Galaxien unter Berücksichtigung von Stößen gasförmiger Wolken

BROSCHE'S investigations concerning the evolution of galaxies are repeated using values for the starting-point which deviate from that of BROSCHE. Especially, a protogalaxy is assumed to consist of gas clouds each of them having a mass of 10⁵ M⊙. The comparison of the results with observation is satisfactory. BROSCHE's interpretation of the HUBBLE sequence as a sequence depending on the angular momentum seems to be questionable.     

Mineralogy and 57Fe Mössbauer spectroscopy of opaque phases in the Neuschwanstein EL6 chondrite

Abstract— This study presents compositional data and ⁵⁷Fe Mössbauer spectra, taken at 295 K and 85 K, of two fragments of the enstatite (EL6) chondrite Neuschwanstein that fell near the famous Neuschwanstein castle (Bavaria, southern Germany) on April 6, 2002. Main silicate minerals are enstatite (Fs 2) and plagioclase (An 20), the main opaque minerals are kamacite and troilite. Small amounts of oldhamite, daubreelite, and schreibersite have been found. The presented Mössbauer data are the first data gathered for an EL6 chondrite. The dominant parts of each Mössbauer spectrum consist of two six‐line patterns due to the presence of ferromagnetic phases kamacite and troilite. In contrast to other chondrites, peaks of other iron species in the central parts of the spectra are missing due to an extremely low content of Fe‐bearing paramagnetic components. The hyperfine interaction parameters for kamacite are internal magnetic hyperfine field H_hf = 333.2 kOe, isomer shift (relative to a metallic Fe foil) IS = 0.01 mm/s, quadrupole splitting QS = 0 mm/s, line width W = 0.41 mm/s. The data for troilite are H_hf = 305.5 kOe, IS = 0.75 mm/s, QS = ?0.85 mm/s, W = 0.34 mm/s.     

A study of ordinary chondrites by Mössbauer spectroscopy with high‐velocity resolution

Abstract— An improvement in the velocity resolution and quality of Mössbauer spectra has been applied to a group of ordinary chondrites. This improvement permitted us to carry out a more detailed study of the iron bearing phases in these samples than has previously been possible. Mössbauer spectra of 11 ordinary chondrites of L and H chemical groups were measured using 4096 channels and presented for further analysis in 1024 channels. Subspectra of the metal grains of several chondrites demonstrated the presence of at least two magnetic sextets related to the main Fe(Ni, Co) phases. Moreover, Mössbauer study of extracted metal grains from Tsarev L5 revealed three sextets and one singlet spectral components related to various α‐Fe(Ni, Co), α‘‐Fe(Ni, Co), α₂‐Fe(Ni, Co), and γ‐Fe(Ni, Co) phases. Each subspectrum of olivine and pyroxene in Mössbauer spectra of ordinary chondrites was fitted by superposition of two quadrupole doublets related to M1 and M2 sites in minerals for the first time. An analysis of relative areas and Mössbauer hyperfine parameters was performed and some differences for L and H chondrites as well as for M1 and M2 sites were observed. Mössbauer parameters of troilite and oxidized iron were analyzed. In contrast to a previous study with 512‐channel spectra, the presence of oxidized iron was found in all chondrites.     

Über periodische Bahnen im eingeschränkten Dreikörperproblem und in der Nähe der Kommensurabilitäten vom Typus (k + 1)/k

The authors, collaborating during the winter 1966/67, performed numerical investigations on form and character of periodic solutions of the restricted problem of three bodies in the Sun–Jupiter-System and in the neighbourhood of the resonances of the (k + 1)/k type. The principal part of these computations which were achieved using a fast IBM-computer refers to the cases 2/1 (Hecuba-gap) and 3/2 (Hilda-group). The results gave new insight into the genealogy of periodic orbits in the regions which do not contain solutions of Poincaré's first genre. Moreover, L. Carpenter tried to develop an analytical theory (here not explicitely described) which leads to convergent trigonometric series for the coordinates of periodic orbits with restricted eccentricities, using the method of general perturbations in rectangular coordinates recently published by P. Musen and himself.     

Die multidimensionale Ungleichung von BERNSTEIN und die Abschätzung der Ableitungen des Gravitationspotentials

In different problems of celestial mechanics it is often necessary to estimate the effect of the truncated higher harmonics of the gravity potential on the motion of a test particle. As a rule the magnitude of this effect is strictly connected with the gravitational acceleration, i.e. partials of the potential. But the mathematical theory of attraction gives the estimations for the potential itself. However, as far as the general term of development (spherical harmonic) possesses a definite reserve of the smoothness, we have succeeded in passing from potential estimations to its partials estimations. The mathematical method based on a multidimensional generalization (obtained here) of an inequality by BERNSTEIN is used. By the way several inequalities connecting different norms of spherical harmonics are proved.     

The Interstellar 2200 Å Band: A Catalogue of Equivalent Widths (Mitteilungen der Universitäts-Sternwarte zu Jena Nr. 151)

Using the data of the Ultraviolet Bright-Star Spectrophotometric Catalogue, the equivalent width of the interstellar absorption band at 2200 Å is derived for 422 stars. A preliminary statistical analysis confirms the good correlation between the equivalent width of the 2200 Å band and the colour excess. The wavelength position of the band centre seems to vary to a small extent.     

Abschätzung von Quasarmassen

The masses of quasi-stellar objects having absorption lines with redshifts larger than the redshifts of the corresponding emission lines are attributed to gas clouds which are moving radially against the quasar. Other forces than the gravitational attraction of the quasars are neglected. The average of the mass of a quasi-stellar object is 5 ⋅ 10¹² 𝔐 ⊙.     

Singularitäten in der Allgemeinen Relativitätstheorie

“Regular solutions of EINSTEIN 's equations” mean very different things. In the case of the empty-space equations, R_ik = 0, such solutions must be metrics g_ik(x^l) without additionaly singular “field sources” (EINSTEIN 's “Particle problem”). – However the “phenomenological matter” is defined by the EINSTEIN equations R_ik – 1/2g_ikR =–xT_ik itselves. Therefore if 10 regular functions g_ik(x^l) are given (which the inequalities of LORENTZ -signature fulfil) then these g_ik define 10 functions T_ik(x^l) without singularities. But, the matter-tensor T_ik must fulfil the two inequalities T ≥ 0, T ≥ 1/2 T only and therefore the EINSTEIN -equations with “phenomenological matter” mean the two inequalities R ≥ 0, R ≤ 0 which are incompatible with a permanently regular metric with LORENTZ -signature, generally.     

Weathering in Antarctic H and CR chondrites: Quantitative analysis through Mössbauer spectroscopy

Abstract— Mössbauer spectroscopy is a very useful tool for identifying ferric iron weathering products in meteorites because of the capability to quantify the relative amounts of ferric iron in them. Mössbauer measurements were made of 33 Antarctic H chondrites (predominately H5) and two paired Antarctic CR chondrites. The primary goals of this study are to determine if Mössbauer spectroscopy can be used to determine which phases are weathering in Antarctic meteorites and if the relative amounts of ferric iron correlate with terrestrial age. Determining which minerals are weathering in ordinary chondrites appears very difficult due to variations in composition for different ordinary chondrites of the same meteorite class and possible problems in preparing homogeneous samples. The analysis of the two paired CR chondrites appears to indicate that metallic iron is predominately weathering to produce ferric iron for this class of meteorite. No correlation is seen between the relative amounts of ferric iron and terrestrial age for ordinary chondrites. One Antarctic H5 chondrite (ALHA77294) with a short ¹⁴C age of 135 ± 200 years from the dating of interior carbonate weathering products does have a relatively low amount of ferric iron, which is consistent with this meteorite being exposed on the surface for a relatively short time.