RADIANTS AND ORBITAL DISTRIBUTION OF TV FAINT SPORADIC METEORS

Анотація

Double station meteor observation using TV CCD unintensified techniques was started in 2013 in Nikolaev astronomical observatory (RI NAO). During observational campaign in 2013-2016 catalog containing 1055 meteoroid orbits has been obtained. Registered meteoroid photometric masses (Kruchinenko, 2012) are between 10^-7 and 10^{- 2} kg. Distribution of radiants, velocities and elements of heliocentric orbits with accent on meteoroids with low masses are analyzed in the work. Comparison with data from meteoroid orbit catalogs SonotaCo, EDMOND and NFC networks is also given. Two kinds of databases/catalogs are distinguished: “narrow field” and “wide field” depending on which type of camera system were used in observations. For analysis of the different catalogs only sporadic meteors were selected. Comparison of sporadic meteoroid radiants and orbital elements for different databases has shown that “narrow field” observations have next typical characteristics:

1) more relative number of low-mass meteoroids (about 30%) than large databases obtained by wide-angle observations;

2) significant increasing of number of low-velocity (V_g < 20 km/s) meteors.

Meteoroids with m < 0.01 g has some specific characteristics different for wide- and narrow-angle observations:

1) “narrow-field” databases have  more orbits with e < 0.8 than “wide-field” ones;

2) aphelion distances in “narrow-field” databases are mostly less than 4.6 au but inclination for such orbits mostly more than 75°, “wide-field” databases show only retrograde with aphelion distances Q > 4.6 predominantly;

3) low-mass meteoroids in “wide-field” databases caused Apex contribution only, notable part of this objects from “narrow-field” data has radiants close to Antihelion source.