Search Publications
Ultraviolet activity in EG Andromedae.
Kaler, J. B.; Hickey, J. P.
The authors show that the symbiotic star EG And is an active variable in the ground-based ultraviolet. In five nights of observation spaced over one year, the full range at Strömgren u was 0m.97, as compared to only 0m.13 at y. The energy distribution in the visual is typical of a cool giant, but a significant component of th…
The extreme LMC supergiant HD 38489 : an optical and ultraviolet study.
Shore, S. N.; Sanduleak, N.
This investigation combines near-infrared, optical, and ultraviolet observations covering λλ1200 - 7000 to study the extremely luminous B star HD 38489 = S134. The star is found to be an evolved B star with Teff ≈ 25,000K, M ≡ 80 - 90 M_sun;, and R ≡ 70 R_sun;. The star is similar to the spectra of some of the superluminous stars of the…
Profiles and intensity ratios of the C IV lambda 1548, 1550 emission lines in planetary nebulae.
Feibelman, W. A.
The C IV resonance doublet at lambda 1548, 1550 is an important diagnostic tool in the study of planetary nebulae. The predicted theoretical intensity ratio of 2:1 is, however, rarely observed in the high dispersion IUE spectrograms. Values of 0.8-2.0 are observed for a sampling of 11 planetary nebulae of various excitation classes and for three p…
Rapid rotation and stellar activity in the triple system HD 165590.
Stern, R. A.; Skumanich, A.
X-ray and ultraviolet observations of the spectroscopic and visual binary HD 165590 are presented. Results show that the spectroscopic binary component has a period of 0.88 day and a near-solar spectral type. A substantial soft X-ray flux for HD 165590 is also found with an X-ray luminosity of 10 to the 30.6th ergs/sec for the system. No obvious p…
The hot do white dwarf HD 149499B : Einstein redshift of a DB progenitor with carbon features.
Sion, E. M.; Guinan, E. F.
High-resolution IUE spectra of the hot DO white dwarf HD 149499B have been analyzed. The mass of the white dwarf needed to fit the measured gravitational redshift is 0.4-0.6 solar mass for a degenerate core composed of carbon based upon using a nonzero temperature mass-radius relation. The resonance doublet of C IV (1550 A) appears to be photosphe…
MG II profile variations of zeta Aurigae.
Kondo, Y.; Chapman, R. D.; Ahmad, I. A.
The authors have observed variations in the Mg II 2800 Å doublet of Zeta Aurigae. The Mg II profiles deviate from simple P-Cygni profiles in that they exhibit an absorption feature consistent with Chapman's (1981) interpretation of C IV absorption as evidence of a column of accretion onto the B star component of the binary. The authors find the op…
IUE observations of the perplexing bipolar planetary nebula NGC 2346.
Feibelman, W. A.; Aller, L. H.
A preliminary analysis of International Ultraviolet Explorer (IUE) low-dispersion spectrograms of NGC 2346, obtained at various phases of the eclipsing nucleus, shows features typical of a high-excitation planetary nebula. Variations in line profiles, intensities, and stellar continuum are observed as a function of time. An orbital period of 16.0 …
The 1982 ultraviolet eclipse of the symbiotic binary AR Pav.
Ake, T. B.; Hutchings, J. B.; Cowley, A. P. +1 more
Observations with the International Ultraviolet Explorer (IUE) of the symbiotic binary AR Pav through its 1982 eclipse show that the hot star is not eclipsed. The hot star is associated with an extended region of continuum emission which is partially eclipsed. The eclipsed radiation is hotter near to its center, with a maximum temperature of about…
Variations of UV chromospheric emissions during a pulsation period ofϱ Puppis (HD 67523)
Fracassini, M.; Pasinetti, L. E.; Castelli, F. +2 more
The peculiar δ Del-variable ϱ Puppis (F6IIp) has been analysed on nine UV high-resolution spectra in the region of MgII h- and k-lines. This analysis has shown: (1) The MgII emission is present during the whole pulsation period and increases with increasing luminosity. Maximum emission fluxes seem to occur at phases 0.96–0.12. (2) The phase shift …
The dust envelope of the Herbig AE star, AB Aur.
Catala, C.
Ultraviolet low resolution observations of a Herbig Ae star, AB Aur, when compared with a theoretical energy distribution for the same spectral type, show the existence of an anomalous extinction, which is believed to be due to a circumstellar dust envelope surrounding the star. The study of this anomalous extinction allows the author to determine…