Vol 34, No 3 (2018)
- Year: 2018
- Articles: 5
- URL: https://journals.rcsi.science/0884-5913/issue/view/11043
Space Physics
Description of Solar Cosmic Ray Propagation in the Interplanetary Medium on the Basis of the Kinetic Equation
Abstract
The propagation of solar cosmic rays in interplanetary space is considered based on the kinetic equation. The expression for cosmic ray density under instantaneous particle injection by a point-like source is obtained. The set of a differential equation system for harmonics of cosmic ray distribution function is obtained starting from the kinetic equation. The cosmic ray transport equation, taking into account the presence of the second harmonic of particle angular distribution, is derived and the solution of this equation is obtained.
Physics of Stars and Interstellar Medium
Actinium Abundance in the Atmospheres of Three Red Supergiants in the Magellanic Clouds
Abstract
The actinium abundance in the atmospheres of red supergiants PMMR23 and PMMR144 in the Small Magellanic Cloud and RM_1-667 in the Large Magellanic Cloud was estimated. The results of spectral observations with the ESO 3.6-m telescope with resolving power R = 30000 were used. Since actinium was not found in the atmospheres of PMMR23 and PMMR144, only the upper limits were set on its abundance: logN(Ac/H) <–15.1 and–15.0, respectively. The estimated abundance of actinium in the atmosphere of RM_1-667 varied with parameters of the atmospheric model from–14.1 to–13.3. The lines of ionized actinium λ 616.475 nm and λ 581.085 nm were used in this analysis.
Dynamics and Physics of Bodies of the Solar System
Statistical Characteristics of Meteoroid Parameters in the Earth’s Atmosphere
Abstract
Statistical characteristics of meteoroids with kinetic energy from 0.1 to 440 kt TNT are estimated based on NASA satellite observations made in 1994–2016. The distributions of the number of falling meteoroids are constructed and analyzed based on the values of their initial kinetic energy, initial velocity, initial mass, altitude, geographic coordinates of the maximum total radiated energy region, and the year of the fall. Correlation dependences “mass–initial kinetic energy,” “maximum total radiated energy region altitude–initial kinetic energy,” and “maximum total radiated energy region altitude–initial velocity (the square of the initial velocity)” are constructed.
Parameters of the Infrasound Signal Generated by a Meteoroid over Indonesia on October 8, 2009
Abstract
The basic parameters (delay time, celerity, duration, oscillation period, and amplitude) of the infrasound signal recorded by 17 stations are statistically analyzed as a function of the horizontal distance between the Indonesian superbolide total radiated energy and the infrasound station location. Fitting dependences of signal parameters on distance are given. Correlation diagrams are constructed and analyzed. The basic parameters of the meteoroid, the corrected value of the infrasound signal celerity, and the average tropospheric-stratospheric wind velocity are estimated.
A Comparison of Values of the Imaginary Part of Aerosol Refractive Index in the Latitudinal Belts of Saturn’s Northern Hemisphere
Abstract
Using the spectrophotometric measurements data of 2015, the relation of values of the imaginary part ni of aerosol refractive index was determined for latitudinal belts 17° N, 33° N, 49° N, and 66° N of Saturn’s disc. A steadily decreasing tendency in the relative ni values when moving northward from the equatorial region of the disk to the latitude 49° N, inclusive, was revealed. The ni values in the 17° N and 49° N belts were found to differ significantly from other latitudinal regions of the giant planet’s disk.