Search Publications

A Search for the Binary Companion of Polaris

Evans, Nancy Remage

Polaris has a spectroscopic orbit determined from an extensive series of observations as well as a more uncertain astrometric orbit. The determination of its mass and evolutionary state is of considerable interest because it is a low-amplitude classical Cepheid with unusual period and amplitude variations. In this study, IUE spectra are investigat…

IUE Observations of X-Ray Selected Stars

Stocke, John; Bergoffen, Martin J.; Walter, Frederick +1 more

UV spectra for four X-ray-selected bright (V less than 10) late-type (F and G) stars have been obtained in both the long- and short-wavelength cameras of the IUE satellite. The stars were selected because they had the largest ratios of X-ray to optical luminosity for their spectral type, with known binaries being eliminated from the sample in orde…

Abundances of Mercury in Sirius and VEGA

Sadakane, Kozo; Takada-Hidai, Masahide; Jugaku, Jun

The resonance line of Hg II at 1942 Å in Sirius and Vega is analyzed quantitatively based on high-resolution UV spectroscopic data. The spectrum synthesis technique is employed. The abundance of Hg in Sirius (log ɛ(Hg) = 2.5±0.5) is found to coincide with that found in the two normal late B-type stars ν Cap and π Cet. On the other hand, the obtain…

The Loss and Reestablishment of the Wind in 66 Ophiuchi in 1985

Peters, Geraldine J.

Mass loss in the Be star 66 Oph during the first six months of 1985, when the star temporarily lost its wind, is discussed. Both IUE and ground-based CCD observations of Hα have been utilized in this study. Observations of Be stars during such periods of "quiescence" are especially valuable for gaining insight into the mechanisms responsible for t…

Empirical Continuum Modeling for IUE Low-Dispersion Spectra

Ayres, Thomas R.; Bennett, Jeffrey O.

The authors describe a numerical procedure for empirically determining a "continuum" level in low-dispersion spectra from the International Ultraviolet Explorer. They developed the technique for the automated fitting of SWP-LO (1150 Å - 2000 Å) spectra of stars of late spectral type, but it is more widely applicable.

Analysis of IUE Data on V426 Ophiuchi: Outburst and Orbital Variability

Szkody, Paula; Mateo, Mario

Time-resolved IUE spectra throughout two orbits of the dwarf nova V426 Oph during quiescence are presented. It is found that the visual and C IV fluxes remain relatively constant during both orbits, whereas the UV coninua and Mg II lines vary by 20-30 percent. The time scales of this variability are discussed. Analysis of other spectra at brighter…

The Long Period K + Be Binary HR 2577 (MWC 827)

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

New spectroscopic observations near Hα and Na I D, along with ultraviolet IUE scans, have been obtained for the K+Be composite system HR 2577. High-precision radial-velocity measures do not support the suggested 58-year orbit of Hendry (1982). The Hα emission from the Be component undergoes considerable variations typical of its class. The presenc…

The IUE Spectrum of CN 1-2 (=PK 326 -10 1): A Southern Counterpart to V1016 Cygni and HM Sagittae?

Feibelman, Walter A.

Low-dispersion IUE spectra confirm that the emission-line object Cn 1-2 is a symbiotic star and not a planetary nebula. The UV spectrum of Cn 1-2 strongly resembles those of V1016 Cyg and HM Sge. The object is correctly identified in the finder field of Allen's Catalogue of Symbiotic Stars (1984) but misidentified in the Catalogue of Galactic Plan…

Spectroscopic Determinations of Surface Gravities of Giant Stars and Ultraviolet Observations of RR Lyrae and X ARIETIS

Bonnell, Jeremiah Tighe

Ultraviolet spectral morphology of the O stars. IV. The OB supergiantsequence.

Walborn, Nolan R.; Nichols-Bohlin, Joy

An atlas of 25 O3 - B8 supergiant spectra in the wavelength ranges 1320 Å - 1580 Å and 1620 Å - 1880 Å is presented, based on high-resolution data from the International Ultraviolet Explorer archives. This remarkably detailed relationship between the stellar-wind profiles and the optical spectral classifications throughout this sequence is emphasi…