A comparative study of type I and type II supernovae . ... Sternberg State Astronomical Institute, Moscow, U.S.S.R. (Received 26 November, 1985) . ... No significant difference between SNe I and SNe II has been found in their radial distribution and frequency of outbursts in spiral galaxies. ... The radial distribution of type Ia SNe in spiral galaxies is only slightly steeper than the one for SNe II, while SNe Ib/c are more concentrated towards the central regions. ...

... It has been largely superceded by MatWeb .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 . ...

Optical characteristics of non-spherical scatterers . ... A list of reviews (under preparation) and links to the databases of Hovenier's and Gustafson's groups on the visible/infrared and microwave light scattering experiments, respectively. ... Light scattering codes . ... Benchmarks in optical properties . Tables of different light scattering characteristics carefully calculated by different codes (methods). Dependence of optical properties on scatterer parameters . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Open symbols refer to data available in the literature. ... The best-fit lines correspond to the exponential-linear relation discussed in Sect. ... We present a new extensive analysis of the old problem of finding a satisfactory calibra- tion of the relation between the geometric albedo and some measurable polarization properties of the asteroids. To achieve our goals, we use all polarimetric data at our disposal. ...

. Mars is "behind" the sun from the earth's point of view and is therefore not visible in the nighttime sky (i.e. its up in the daytime). Venus it at greatest elongation and appears in the western sky as a bright object for 2-3 hours after sunset .

... Please let me know if you find any errors. \begin{equation} \mathrm{lb}(x) \equiv \log_{\rm 2}(x) \end{equation} . ... begin{equation} \log_{a}(1) = 0 \end{equation} . ... begin{equation} \log_{a}(x) = \frac{\log_{b}(x)}{\log_{b}(a)} \end{equation} . ... begin{equation} \sin(\alpha) \equiv \frac{\mathrm{opp}}{\mathrm{hyp}} \end{equation} . ... begin{equation} \sin(\alpha) = \frac{1}{2 \mathrm{i}} \left( \mathrm{e}^{\mathrm{i} \alpha} - \mathrm{e}^{-\mathrm{i} \alpha} \right) \end{equation} . ...

... A universal physical relation for quasars . ... Harvey Tananbaum and his collaborators have first observed a relation between the soft X-ray and the optical/ultraviolet emission in AGN in 1979. Such relation is nonlinear, and it is usually parameterized as dependence between the logarithm of the monochromatic luminosities at 2500 †Е ( L 2500†Е ) and 2 keV ( L 2keV ) . ... Yet, the dispersion along the L 2500†Е тАУ L 2keV relationship is found to be rather high, typically ~0.35тАУ0.4 in log units. ...

This is a tabulation of interstellar dust scattering properties dertermined from observations of various astrophysical objects (eg., ... Almost all studies in this field aim to determine the single scattering albedo (a) and scattering phase function asymmetry (g = <cos( )>) as different wavelengths. ... Plot Details . ... Plot details links to a page describing the studies included in the plot, the radiative transfer model used in each study, and an ascii listing of data plotted. ...

... Early on, our interest in chirping analysis functions was motivated by a different kind of chirping phenomenon: chirping due to perspective. ... Our interest in radar, however, drew us toward processes that are more accurately analyzed by linear-FM chirplets. ... We have also constructed other chirplet transforms, such as a three-parameter Doppler chirplet representation that models a source producing a sinusoidal wave, while moving along a straight line (e.g. a train whistle). ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...