We discuss a new mechanism of dust acceleration that acts in turbulent magnetized medium. The magnetohydrodynamic (MHD) turbulence includes both fluid motions and magnetic fluctuations. We show that while the fluid motions bring about grain motions through the drag, the electromagnetic fluctuations, can accelerate grains through resonant interactions. In this paper we discuss grain acceleration...

We present the mass distribution of interstellar grains measured in situ by the Galileo and Ulysses spaceprobes as cumulative flux. The derived in situ mass distribution per logarithmic size interval is compared to the distribution determined by fitting extinction measurements. Large grains measured in situ contribute significantly to the overall mass of dust in the local interstellar cloud. Th...

The behavior of linear and nonlinear dust acoustic waves (DAWs) in an unmagnetized plasma including inertialess electrons and positrons, ions, and mobile positive/negative dust grains are studied. Reductive perturbation method is employed for small and finite amplitude DAWs. To investigate the solitary waves, the Korteweg–de Vries (KdV) equation is derived and the solution is presented. B...

We analyse the ionization state of the magnetohydrodynamically turbulent protoplanetary disks and propose a new mechanism of sustaining ionization. First, we show that in the quasi-steady state of turbulence driven by magnetorotational instability in a typical protoplanetary disk with dust grains the amount of energy dissipation should be sufficient for providing the ionization energy that is r...

We examine the thermal infrared spectra of large dust grains composed of amorphous and crystalline olivine. Strong resonances in the refractive indices result in detectable spectral structure even when the grain is much larger than the wavelength at which it radiates. We apply this to the thermal infrared spectra of compact amorphous and crystalline silicates. The weak resonances of amorphous s...

The path to understanding star formation processes begins with the study of molecular clouds. outskirts these clouds are characterized by low column densities that allow penetration ultraviolet radiation, resulting in a non-negligible ionization fraction and charging small dust grains mixed gas; this diffuse phase is then coupled ambient magnetic field. Despite general assumption gas tightly co...

Observations of the weak polarization of light from nearby stars, reported by Tinbergen (1982), are consistent with polarization by small, radius<0.14 μm, interstellar dust grains entrained in the magnetic wall of the heliosphere. The region of maximum polarization is towards ecliptic coordinates (λ,β)∼(295,0), corresponding to (l,b) = (20,–21), while the dust cone direction shows a marginally ...