Results from several persistent train spectra intercompared

Some results following from two contemporary photographical programs (Slovakia and Japan) for persistent meteor train spectra are compared. It shows that even though both programs are not too different according to their lenses and films used, the spectral interval detected is very different. In this respect prism as a dispersion element is more favourable than the grating with blaze wavelength near 610 nm. However, some results previously assumed as typicai for presented persistent trains-e.g. the forbidden Herzberg O₂ emission, the NO₂ continuum and OH red emissions-seem to be substanciated especially due to higher and linear dispersion of those grating spectra.     

Colliding winds model of X-ray radiation in SS 433: analysis of X-ray eclipses

Interpretation of X-ray eclipses in SS 433 binary system in the framework of wind-wind collision model yields high value of mass ratioq =m _x /m _v > 1 which implies high mass of relativistic objectm _x > 8M .     

The flare star PP Ori

We give the results of photographic, photoelectric, and spectral observations of the flare star PP Ori. The 109 photographic observations used, which were obtained on the 40 Schmidt telescope of the Byurakan Observatory over a period of about 20 years, and four spectra obtained on the same telescope with a4° objective prism show no variation in brightness. Photoelectric observations in the UBVR bands using the 50cm and 60cm telescopes of the high-altitude Maidanak station of the Tashkent Astronomical Institute in 1987 and 1989 give grounds for suspecting a variation in brightness much larger than observational errors. Spectral observations of the star PP Ori made on the 2.6m telescope of the Byurakan Observatory show weak H emission. The results of all these observations show that PP Ori is an Orion variable of spectral class K7-M0 with absolute visual magnitude7 ^m 5–8 ^m 5.Translated fromAstrofizika, Vol. 38, No. 2, 1995.     

Searches for bright-rimmed clouds with IRAS point sources

We have carried out systematic surveys for small bright-rimmed clouds associated with IRAS point sources in/around HII regions. They are candidate sites for star formation due to radiation-driven implosion.     

Mathematical investigation of bode's law and quantilization of gravity

A non-static General Relativistic mathematical solution for the gravitational field around a star is obtained. From this mathematical solution, the orbits of the planets around the Sun are calculated and compared with Bode's law and the mean distances of the orbits, the origin of the Moon is deduced, and a theory for quantilization of gravity is concluded.     

Existence of the continuations in theN-body problem

The method of obtaining the estimates of the maximalt-interval ( _–, ₊) on which the solution of theN-body problem exists and which is such that some fixed mutual distance (e. g. ₁₂) exceeds some fixed non-negative lower bound, for allt contained in ( _–, ₊), is considered. For given masses and initial data, the increasing sequences of the numbers _k , each of which provides the estimate ₊ > _k , are constructed. It appears that if ₊ = +, then .     

On depth-dependence of photospheric oscillations

We report on results from photographic observations of photospheric oscillations as a function of depth. Using rms-values and power-spectra from shifts of entire line-profiles, we find qualitatively an increase of the velocity-amplitude with increasing height. We get more quantitative informations by comparing measured asymmetries of line-profiles with calculated ones derived from Voigt-functions containing a depth dependent velocity-field.We find the scale-height H ₀ of photospheric velocity oscillations to be 930±100 km. This result is to be compared with H ₀ = 1100±200 km obtained by Canfield (1976), who used velocity weighting functions of the line centres.Further, we show that a general observed line asymmetry of medium strong lines (c-shape) does not depend on the phase of oscillations.Mitt. aus dem Kiepenheuer-Institut Nr. 178.     

Magnetic reconnection induced by Kelvin Helmholtz instability

MHD simulation study is performed to investigate magnetic reconnection induced by the Kelvin Helmholtz instability in the initially sheared magnetic field geometry as well as in the uniform magnetic field geometry. Slow mode rarefaction structures seen in the uniform field case are not observed in the sheared field case. Dynamo action is less prominent and the conversion of plasma flow energy into the other forms of energy is also smaller in the sheared field case than in the uniform field case. Momentum transport is mostly due to the hydrodynamic stress in the sheared field case, while the electromagnetic stress is dominant in the uniform field case. The long term evolutions are also markedly different in the two cases. In the uniform field geometry, the magnetic field lines twisted due to the Kelvin Helmholtz instability become reconnected and flattened so that they resume the straight field line structure which resembles the initial field geometry. The magnetic field, however, is not uniform with smaller intensity in the central region where the pressure balance is partially maintained by the enhanced thermal pressure. In the initially sheared magnetic field geometry, magnetic reconnection continues to operate until the end of the simulation and the conversion of the flow energy into the thermal energy is still seen.     

Structure in the solar corona from radio scintillation measurements

Since the 1950s, a wide variety of radio observations based on scattering by electron density fluctuations in the solar wind has provided much of our information on density fluctuations and solar wind speed near the source region of the solar wind. This paper reviews recent progress in the understanding of the nature of these density fluctuations and their relationship to features on the Sun. The results include the first measurements of fine-scale structure within coronal streamers and evidence for structure in solar wind speed in the inner corona.     

A filament eruption and accompanying coronal field changes on November 5, 1992

An H filament eruption on November 5, 1992 was fully observed in H with the Hida Flare Monitoring Telescope, while Yohkoh's Soft X-ray Telescope observed the pre- and post-eruption evolution of the coronal magnetic fields. From the H data, including the red and blue wings, we have reconstructed the rise of the filament, including trajectory, velocity, and acceleration. In combination with the Yohkoh data this reconstruction suggests that the filament had several interactions with other coronal magnetic fields during the eruption. The Yohkoh data also shows pre-eruption changes in the coronal fields and several post-eruption bright coronal structures. The pre-eruption changes are interpreted as a partial opening of the corona, indicating that it is not necessary to have a complete opening of the corona in order for a filament to erupt and we discuss the several possible contributions from emerging flux. The post-event bright coronal structures are compared with theory and with a cleaner filament eruption event on July 31, 1992. These comparisons suggest that, although there are many similarities, it is hard to completely reconcile the observations with the existing theory.