New lUE observations of the reflection nebula IC 435 are presented, and the scattering properties of the nebular dust grains are derived. ... The UV observations plus optical data from the literature determine the most likely star-nebula geometry, the nebular dust density distribution, and the values of the albedo and the phase function asymmetry for the dust grains. ... ADS Citation Query . citations = 51 . citations vs. year [year,citations] . ...

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: Copying Calibration Tables - Up: Calibration, the ATCA, and Previous: Determining Gains and Bandpass . ... This parameter can be used as an alternative way of specifying the XY phase of the antennas. ... Unless you explicitly turn off solving for XY phase in gpcal , then the only important XY phase value is that for the reference antenna. ... means that gpcal will solve for the XY phase of the reference antenna. ... By default it solves for all XY phases, except for the reference antenna. ...

... 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. ...

. Next: Spectrum Up: R CORONAE BOREALIS STARS Previous: HISTORICAL BACKGROUND . Figure: The light curve of RCoronae Borealis during a fading event in 1859 . RCB stars were first identified by their characteristic light curves. A part of the light curve of RCrB itself, taken from over a century of observations compiled by Ludendorff (1906) is shown in Figure 1 . Spectrum . Galactic distribution and absolute magnitudes . Numbers and distances . Simon Jeffery . 2002-01-25

... Based on the measurements of the Stokes parameters in the continuum and in the broad 0.6563 nm hydrogen emission line obtained with the 6-m telescope for the Seyfert galaxy Mkn 6, secular variability of the hydrogen line profile polarization was discovered; a time lag of less than 2 days between the continuum flux and the polarized continuum emission was determined which corresponds to the size of the region where the polarization of the continuum occurs, less than 0.001 pc. ...

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