Search Publications
Redshifts of high-temperature emission lines in the far-ultraviolet spectra of late-type stars.
Jordan, C.; Stencel, R. E.; Linsky, J. L. +4 more
High-dispersion IUE spectra of six late-type stars exhibit small but statistically significant differential redshifts of high-temperature emission lines, like Si IV and C IV, with respect to low-temperature lines like S I and O I. A well-exposed, small-aperture spectrum of the active chromosphere binary Capella (Alpha Aurigae A: G6 II+F9 III) esta…
Star formation in blue galaxies. I. Ultraviolet, optical, and infrared observations of NGC 4214 and NGC 4670.
Gallagher, J.; Fabbiano, G.; Huchra, J. P. +4 more
NGC 4214 and NGC 4760 have been observed between 1150 A and 1950 A with the IUE satellite, and new infrared and optical broad-band photometry have been obtained. The spectra of both galaxies are dominated by O stars, and, in the spectrum of NGC 4214, the C IV 1550 A line exhibits a P Cygni profile indicative of hot stars with large mass-loss rates…
Observations of active chromosphere stars.
Stencel, R. E.; Bopp, B. W.; Africano, J. L. +2 more
It is pointed out that spectroscopic signatures of stellar chromospheric activity are readily observable. The present study is concerned with new photometric and spectroscopic observations of active-chromosphere RS CVn, BY Dra, and FK Com stars. Attention is given to the first results of a synoptic monitoring program of many active chromosphere st…
Far-ultraviolet emission lines in U Cephei : evidence for a hot, turbulent circumstellar envelope.
Plavec, M. J.
U Cephei is a classical semidetached eclipsing binary of the Algol type, whose unusually high level of activity in the optical spectrum has long been recognized. This paper reports detection of numerous emission lines in the far-ultraviolet spectrum. For the first time, the line-emitting region has been studied both in emission and in absorption. …
The angular diameters, effective temperatures, radii, and luminosities of 10 Wolf-rayet stars.
Underhill, A. B.
The effective temperature of a normal star with an absorption-line spectrum is a parameter which represents the total amount of radiative energy emerging from each square centimeter of surface of the star. Effective temperatures have been obtained for 10 Wolf-Rayet stars by means of ultraviolet energies determined from high-resolution Internationa…
Ultraviolet continuum and H2 fluorescent emission in Herbig-Haro objects 43 and 47.
Schwartz, R. D.
IUE short wavelength spectra are presented for the low excitation Herbig-Haro objects HH 43 and HH 47. In the former, several emission lines in the Lyman band of H2 from an excited state are observed which are due to fluorescence from the H Ly-alpha line pumping a lower state (that is in turn excited by a low-velocity shock wave). No evidence of h…
Reddening indicators for quasars and Seyfert 1 galaxies.
Grandi, S. A.
It is pointed out that a determination of the reddening caused by intervening dust is a prerequisite to understanding the astrophysics of the broad line emission in quasars and their close cousins Seyfert 1 galaxies. Previous discussions of the reddening question have tended to be incomplete. The present investigation represents an attempt to asse…
The binary central star of the planetary nebula LT-5.
Feibelman, W. A.; Kaler, J. B.
The authors have found with the IUE that the true central star of the giant planetary Longmore-Tritton 5 (339+88°1) is a binary companion to the G5 star SAO 82570. The slope of the energy distribution curve indicates that the star may be one of the hottest known. The Mg II doublet associated with the G star is very strong, consistent with the exis…
The planetary nebula IC 3568 : a model based on IUE observations.
Feibelman, W. A.; Harrington, J. P.
The planetary nebula IC 3568 has been observed at both low and high dispersion with the IUE satellite. The spectrum of the star shows strong P Cygni profiles due to an 1840 km/s stellar wind. The nebular spectrum shows lines of He II, semi-forbidden C III, C IV, semi-forbidden N III, and semi-forbidden O III. The spatial distribution of the gas ha…
The pulsation properties of DB white dwarfs : a preliminary analysis.
Hansen, C. J.; Winget, D. E.; Fontaine, G. +2 more
Preliminary numerical results are given for the nonradial g-mode pulsation properties of evolutionary DB white dwarf models, where the solutions include the fully nonadiabatic equations for modes corresponding to the spherical harmonic index l = 1-3. For each of the model sequences examined, a nonradial g-mode instability strip approximately 3000 …