Astronomical School’s Report, 2020, Volume 16, Issue 1, Pages 8–15
The physics of space intrusions. I. Features of the trajectories
Zhilyaev B.E., Vidmachenko A.P., Steklov A.F., Pokhvala S.M., Verlyuk I.A.
The Main Astronomical Observatory of the NAS of Ukraine, 03143, Academician Zabolotny str., 27, Kyiv, Ukraine
This paper presents theoretical developments of some issues in the physics of space intrusions. We report the discovery of a new effect – variations in brightness and “wobbling” in the meteor trail. The frequency of the variations of brightness (fc) and wobbling (fm) that can be measured is important information parameters that allow us to obtain estimates all the characteristics of the meteor if its height and speed are known. Basic two-side intrusion observations automatically determine both the height and speed of the intrusion. We offer a new “tuning technique” that allows determining the meteor characteristics during one-side observations. The essence of a new technique is to fine-tune the initial parameters of the simulation model of intrusion until the calculated and measured frequencies fc, fm coincide. We found that rotation plays an important role in the dynamics of meteors; in particular, they can burst in due to centrifugal forces that exceed the strength of the material. In the case of one-side observations, we construct a grid of intrusion models using the Impact 4A software program on the plane of the primary “mass–speed” meteoroid. As a result of modelling, we find the height at which the frequency ratio fc/fm coincides with the value found from measurements for exploding meteoroid. The paper describes the characteristics of the space intrusion of a meteor in Kyiv on August 12, 2019, 22:52:57 UT. The amplitude of the brightness fluctuations was found about 0.1 magnitudes, the amplitude of the wobbling of about 4 arc seconds. Using the Impact 4A software program the preatmospheric velocity was evaluated ∼40 km/sec; the mass of the meteoroid was evaluated approximately 0.45 kg. This meteoroid reached maximum light at 82.2 km and ablated partially. We find estimates of a residual mass of about 10 grams and a residual speed of about 20 km/s. We found that the radius of the helical path of the meteor at this height is about 1.5 meters. The meteoroid reached a critical value of the speed of rotation on the surface. At this moment, a meteoroid exploded and destroyed.
Keywords: space intrusions; methods: observational; processing techniques: photometric; objects: meteors
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