Вісник Астрономічної школи (Oct 2020)

The physics of space intrusions. I. Features of the trajectories

  • B. E. Zhilyaev,
  • A. P. Vidmachenko,
  • A. F. Steklov,
  • S. M. Pokhvala,
  • I. A. Verlyuk

DOI
https://doi.org/10.18372/2411-6602.16.02
Journal volume & issue
Vol. 16, no. 1
pp. 8 – 15

Abstract

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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 (f_c) and wobbling (f_m) 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 f_c, f_m 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 f_c/f_m 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.

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