Next: Polarization efficiency: size/shape/orientation effects Up: Optical properties of cosmic Previous: The 2175? feature . To model the interstellar polarization one needs to calculate the forward-transmitted radiation for an ensemble of non-spherical aligned dust grains. ... Let non-polarized stellar radiation passes through a dusty cloud with a homogeneous magnetic field. ... The angle between the line of sight and the magnetic field is ( ). ... where the angle is connected with and ( ). ...

Next: EVOLUTION MODELS Up: EXTREME HELIUM STARS: PULSATION Previous: EXTREME HELIUM STARS . The characteristic surface properties, effective temperature , surface gravity and composition , of EHes have been summarized by Jeffery (1996). ... Helium: ( ) By definition, helium dominates the atmospheric abundances. ... This is supported by a correlation between N and Fe abundances in EHes. ... Next: EVOLUTION MODELS Up: EXTREME HELIUM STARS: PULSATION Previous: EXTREME HELIUM STARS Simon Jeffery . ...

... In brief: the frequency-dependent radiative transfer equation is solved for a dust under assumption of spherically-symmetric geometry for its distribution taking into account particle size distribution and quantum heating effects for the very small dust particles. ... Table: Model parameters for IRAS04296+3429. ... parameter . ... hot dust shell) . ... The best fit to the spectral energy distribution of IRAS04296 is shown by heavy solid line (see Table2 for details concerning parameters of the model...

... Abstract: We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. ... As a general result, clumpy models are less opaque than the corresponding homogeneous models. ... 0.00 0.15 0.50 0.1 0.5 1.0 2.0 5.0 10.0 0.25 X . ... We have also produced several homogeneous models, to compare to the clumpy models. ... Homogeneous and clumpy models with the same tauV have the same dust mass. ...

Authors: Yu.G. Shevelev , V.A. Marsakov , . ... We have constructed and investigated properties of metallicity function of disk stars with different ages, proceeding from the statistically restored real altitude distributions of stars at the solar galactocentric distance. It is shown that the metallicity distribution of stars in each age range is not of Gaussian form, but it may be considered as a superposition of two normal distributions centered at -0.2 and 0.0 dex. ...

... It has been largely superceded by MatWeb . Conversion Factors . Material properties . Physical constants . Astronomical constants . This table gives conversion factors to convert various units to their SI equivalents. ... The units are SI. This is a short list of physical constants in SI units. ... Boltzmann constant . ... Gas constant . ... Mass . ... Plank's . ... Radiation constant . ... This is a short list of astronomical constants in SI units. ... Sun . ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...