5 research outputs found
Long-lasting activity of asteroid (248370) 2005 QN 173
We present the results of observations of asteroid (248370) QN
obtained during July 2021 - January 2022 with three telescopes. Our analysis
revealed the presence of the dust tail for about half of a year. The direct
images of the asteroid were obtained with broad-band filters. No emissions were
revealed in the spectra, and the spectrum of the asteroid closely matched that
of a C-type asteroid. Created color and linear polarization variations along
the tail were analyzed. The asteroid demonstrated a redder color compared to
the Sun. Dramatic changes in dust productivity obtained in different filters
were not detected. The color changes from to over the
coma, and the linear polarization degree varies from about \% to \%
and from \% to \% at the phase angle of and
. The total dust mass ejected until the latest observation on
October 10 is ~kg, with a maximum rate of 2.6~kg\,s
based on the Monte Carlo modeling of the dust tail. The estimated asteroid size
is 1.3~km. It is shown that large particles are concentrated around the
nucleus, whereas smaller ones dominate in the tail. The evolution of (248370)
QN orbit and the orbits of the sample of the 464 short-periodic comets
were followed. Ten of them approached the asteroid's orbit. These objects are
not genetically related, despite the very close distance of their orbits for a
relatively long time.Comment: pages 13; 5 tables; figures 1
Density, porosity and magnetic susceptibility of the Košice meteorite shower and homogeneity of its parent meteoroid
Bulk and grain density, porosity, and magnetic susceptibility of 67 individuals of Košice H chondrite fall were measured. The mean bulk and grain densities were determined to be 3.43 g/cm3 with standard deviation (s.d.) of 0.11 g/cm3 and 3.79 g/cm3 with s.d. 0.07 g/cm3, respectively. Porosity is in the range from 4.2 to 16.1%. The logarithm of the apparent magnetic susceptibility (in 10−9 m3/kg) shows narrow distribution from 5.17 to 5.49 with mean value at 5.35 with s.d. 0.08. These results indicate that all studied Košice meteorites are of the same composition down to ∼g scale without presence of foreign (non-H) clasts and are similar to other H chondrites. Košice is thus a homogeneous meteorite fall derived from a homogenous meteoroid.Peer reviewe