Method for determination of equatorial coordinates of a bright bolide detected with wide-angle low-sensitive home guard camera on 9 August 2020 above Kyiv is presented. Due to low sensitivity of the camera there were no objects for comparison in the frames with the bolide, and sky was obstructed more than a half by the crown of threes. For a search of objects of comparison with known equatorial coordinates we proposed to use the images of the Moon and Mars, which systematically got into frames during the next month – September. The corresponding formulae are presented. The precision of the bolide’s equatorial coordinates calculation were tenths of degree at field of view of the camera 100°, and the trajectory angular length was near 15°. The bolide was very slow, and according to calculations did not belong to the Perseid meteor shower, which was active during the observations.
Abstract. InSb wafers of n-type conductivity were annealed at 300, 370 and 400 °C for 30 min in an open tube system under flowing argon ambient. The conductivity type conversion are revealed for the first time in samples with the electron concentration ~1.0·10 14 cm -3 for all annealing temperatures. Experimental evidences have been obtained that this phenomenon has a bulk character. In annealed samples the spectral response exhibits pronounced increase in the short-wave region. The effect of annealing on electrical and photoelectrical properties of n-InSb has been explained by formation of In Sb antisites.
The performance of p + -InAsSbP/n-InAs infrared (IR) photodiodes prepared by liquid phase epitaxy technique (LPE) is investigated. The current-voltage and capacitance-voltage characteristics, photoresponse and noise spectra are investigated in the temperature range 77-300 K. The trap-assisted current is calculated and compared with experimental data. It is found that at near-room temperatures and small reverse biases U ≤ 0 .2 V experimental I-U characteristics are determined by diffusion and generation-recombination mechanisms. The trap-assisted tunnelling is shown to be dominant at higher reverse biases. The heterojunction photodiodes have superior photoresponse spectra in comparison with homojunction photodiodes and high threshold parameters.
We present the method for kinematic and photometric processing of results of single-station video observations of a unique bright fireball (bolide or space vehicle remnant) carried out in bad observational conditions. Due to the low sensitivity of the video camera, lots of star-shaped artifacts in the camera detector on the one hand, and the bright Moon of -10.95 mag, which was directly in the camera field of view on the other, the star images were completely absent in all the frames. It is demonstrated that using the averaging and summing algorithms applied to the whole set of frames and the display of different dynamic layers of intensity allowed us to find and identify 45 reference stars, the faintest of which were of 5.4…5.7 mag. Due to the visibility of the point of closest approach of the object trajectory to an observer, which corresponds to the maximum angular velocity, in the camera field of view and the performed modeling, we obtained the next data about the fireball from the single-station detection after the video processing. The fireball fall lasted longer than 12 seconds, the angular length of the trajectory exceeded 60 deg, maximum angular velocity was computed as 7.4 deg/sec. It was shown that the space body in the point of maximal approach could lose near 32 percent of its initial velocity. Visibility of the maximal approach point allowed us to calculate the right ascension and declination of the visible radiant as 272.0 and -0.8 deg, respectively. The luminosity of the fireball was varying in the range of -5.5 to -8.5 mag. All the calculations performed did not allow us to unambiguously identify the fireball as a meteoroid or as a cosmic debris fragment.
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