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Weighted Slit Extraction of Low-Dispersion IUE Spectral Data

Bohlin, R. C.; Kinney, A. L.; Neill, J. D.

standard extraction for low-dispersion spectra in the final IUE archives. In order to properly weight the data within the extraction slit and obtain the optimal evaluation of the true spectrum, a noise model is derived for IUE data. The exclusion of cosmic rays is demonstrated and the improvement in signal-to-noise ratio is quantified for spectra …

PB 6 and Its Central Star

Feibelman, Walter A.; Shaw, Richard A.; Kaler, James B. +1 more

It is found that the hot nucleus of the Type I southern planetary nebula PB 6 is a member of the rare class of O VI stars. The blended O VI 3811 + 3834 emission doublet is one of the strongest seen, with an equivalent width (relative to the stellar continuum) of about 400 A. The helium, nitrogen, and carbon abundances are all very high for the cor…

The Halo Planetary Nebulae M 2-29 and BB-1

Pena, M.; Torres-Peimbert, S.; Ruiz, M. T.

Spectrophotometric data for the two planetary nebulae are given and compared to the data for a well-understood type of planetary nebula (PN) for classification and measurements of abundances. M 2-29 and BB-1 were observed in the wavelength ranges of 3500-5000 and 6000-7500, and the visual calibrated spectra and emission-line fluxes are given along…

Carbon in Orion

Walter, D. K.

The carbon abundance in the Orion nebula is redetermined from a detailed study of UV spectra in the IUE archives. Temperature and electron density gradients were derived for the inner 5 arcmin of the nebula using new and existing observational data. These temperatures and densities were used to calculate the carbon abundance for 19 positions large…

Optical and Ultraviolet Spectroscopy of Three F + B Binary Stars

Parsons, Sidney B.; Dempsey, Robert C.; Bopp, Bernard W.

Optical and ultraviolet spectroscopy is presented for three F + B objects that are members of the first group of strongly interacting, F II + B systems. The data obtained confirm that HD 59771, HD 242257, and CoD -30 5135 are all binary star systems consisting of a luminous F-type component and a B star. Strong, variable H-alpha emission is seen i…