We examined the characteristics of the SNU uvby, Hβ Hβ filter system through the computation of theoretical photometric indices and the transformation of the observed instrumental system to the natural and standard systems.
Magnetic reconnect ion is studied numerically by means of a two dimensional MHD code. The initial magnetic field configuration is the two-dimensional dipole field, and the simulation model involves magnetic reconnect ion driven by the magnetized plasma flow. Strong plasma jetting, plasmoid formation and its fast ejection are observed in the downstream region. The dependence of reconnection rate on the incoming energy flux is found to be very sensitive, while the magnitude of the resistivity does not influence much on the reconnection rate. The simulation results are discussed in the context of the geomagnetic substorm.
Two theories, the adiabatic and the isothermal, of galaxy formation are surveyed with regard to the current observational constraints, Some advantage of non-baryonic theory compared with the usual baryonic theory is discussed.
We derived initial mass functions (IMF) of massive stars in three different regions of spiral arms within 2.5kpc from the sun. The derived IMF slope β β of Local arm stars is found to be −2.09∼−2.06 −2.09∼−2.06 , very close to that of Bisiacchi et al. (1983). For Sagittarius-Carina arm stars β β ranges from -1.77 to - 1.72 which is close to that of overall stars given by Germany et al. (1982). Possible causes inducing the regional difference in IMFs are discussed.
We analyzed the reddening of 873 bright G and K stars from the DDO photometry in combination with MK spectral classes and (B-V) colors. About a quarter of the sample stars have DDO indices beyond the limits of DDO calibrations. To extend the reddening determination to all stars, we applied a scheme for reddening determination of field G and K stars by using the DDO calibrations (Janes 1977, 1979b) and MK-(B-V) relation of FitzGerald (1970).
Four observational astronomical item, have been pilottested with a 150mm refracting telescope in order to layout the detailed procedures for the suggested (inquiry) activities listed in the high school earth science curriculum and to contrive some adequate instructions for students stressed on how to make proper treatments with the collected materials. The tested items were of sunspots' motion, the size of lunar craters, the Galilian satellites' revolution, and the galactic distribution of stars. Following series of activities are suggested with respect to the way of collecting observational data and of giving proper instruction to students in class: 1) Photography and other material, he made by teacher and/or extracurricular group of students; 2) Replicas (xeroxed, photographs, Or slides) he made from the collected materials, '0 that they are available to all the students in class; 3) Quantative analyses, be taken as student' activity.