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

The J, H, K, and L profiles of Comet Halley taken on January 15, 1986 using the liquid nitrogen cooled InSb detector mounted on the 1.5-m Tenerife Infrared Flux Collector, are discussed. The J and H emission is shown to be strongly dominated by grain scattering of the solar continuum, while grain thermal emission is strong at K and becomes

Near-infrared photometry for the red-giant and horizontal branches in M4, obtained with the InSb detector mounted on the 1.54-m Tenerife Infrared flux collector, are presented. The red giant branch is shown to be displaced from the corresponding trend for M92, confirming earlier work, and implying an intermediate to high cluster metallicity. The