Tajikistan fireball network and results of photographic observations

The fireball network was created in Tajikistan with the aim of obtaining new data on the near-Earth meteoroid environment concerning large bodies, entering in the Earth’s atmosphere and producing fireballs, as well as new observational data on the activity of known meteor/fireball showers. The network consists of five observational stations equipped with the photographic fireball and digital all-sky cameras. Distances between the stations are from 53 to 184 km and the area covered by monitoring is around 11000 km2. For astrometric reduction of fireball photographs, a technique has been developed that allows positions of object details to be determined at an accuracy of about 1′, which is a sufficiently good result for negatives of this scale. In the method of photometric reduction, a dependence of measured widths of diurnal star trails on their magnitudes is used. As a result of processing of multi-station photographs of more than 200 fireballs, photographed by the fireball network for 2006–2013, the data on their atmospheric trajectories, coordinates of radiants, velocities, decelerations, orbits in the interplanetary space, light curves, photometric masses, and densities, as well as on the nature of origin of meteoroids which produced the fireballs are obtained; membership of the fireballs to the known fireball/meteor showers is determined. A brightness of the majority of fireballs is within the maximum absolute magnitude range from −5 to −8. It is shown that 62% of fireball-producing meteoroids have a cometary origin and the remaining 38% are of an asteroidal nature. The greater part of the photographed fireballs belongs to the known meteor/fireball showers, while the lesser part (almost 30%) relates to the sporadic background. The obtained results will noticeably replenish the world database with new information on fireballs and are required for solving contemporary astronomy problems associated with studying meteoroid environment in the near-Earth space and the asteroidal-cometary hazard as well as for discovering genetic links between small bodies of the Solar System.