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The paper presents low resolution spectra in the range of 3700 to 7100 A, taken with the Royal Greenwich Observatory Image Photon Counting System on the 2.5-meter Isaac Newton Telescope, at the Observatory of El Roque de los Muchachos on the night of September 25/26, 1985. At this epoch, the Comet had a heliocentric distance of 2.41 AU. The paper

For circumstellar systems with an orientation perpendicular to the plane of the sky, and under some simplifying assumptions, the surface brightness integral equation can be formally inverted. Application of the resulting equation to the disk of dust surrounding the star β Pictoris seems to reveal a radial distribution of dust going approximately

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Using the H-II region H-alpha emission detected in high-resolution long slit spectra of the normal spiral NGC 6946 out to 6 kpc from the center, and along 8 radii equally spaced in angle, velocity curves of the circumnuclear zone are obtained. The curves show that the radial velocity gradient, and the limiting radial velocity along the minor axis

The authors have measured the intensities of several diffuse interstellar bands in intermediate resolution spectra (0.35 - 0.65 Å) of heavily reddened early-type stars in three associations: Cas OB6, Be 87, and Cyg OB2. The extinction is attributed mostly to material at intermediate densities between molecular clouds and the diffuse medium. The