International Ultraviolet Explorer Atlas of B-Type Spectra From 1200 to 1900 \AA

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Session 22 -- Stellar Spectroscopy, Atmospheres, Models, Intrinsic Variables, Theory, Part II
Display presentation, Tuesday, June 13, 1995, 9:20am - 6:30pm

[22.21] International Ultraviolet Explorer Atlas of B-Type Spectra From 1200 to 1900 \AA

J.~Wm.~Parker (NRC \& Hughes STX, GSFC/LASP), N.~R.~Walborn (STScI), J.~S.~Nichols (CSC, GSFC), T.~R.~Gull (GSFC/LASP)

We present an atlas of B-type spectra consisting of short-wavelength, high-resolution data from the International Ultraviolet Explorer archive. The atlas presented here is designed to complement the widely used O-star atlas from the same source (Walborn, Nichols-Bohlin, \& Panek 1985, NASA Reference Publication 1155), and it completes the OB natural group, i.e.\/ , to spectral type B3 for the main sequence and giants, type B5 at class Ib, and B8 at Ia, which is also the most relevant domain for stellar-wind effects among normal B-type spectra. A primary objective is to chart in detail the gradual disappearance of the stellar-wind features in normal spectra as a function of spectral type and luminosity class. As in the O-star atlas, which first demonstrated the strong correlation between the optical spectral types and the UV wind behavior in the majority of the stars, the principal selection criterion was the existence of high-weight optical spectral classifications, which are quoted here without any revisions based upon the UV data. Some peculiar categories also are displayed including a number of hypergiants, stars of types BN/BC (and including three of type O9.7 acquired since the O Atlas), and stars with enhanced winds. 86 images have been selected from the IUE archive for the atlas. The processing and presentation is as similar as possible to the O-star atlas, with the data rectified and rebinned to a uniform resolution of 0.25 \AA, and printed at a scale of 10~\AA/cm.

Atlases will be available at the meeting for distribution.

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