Search Publications
The determination of the mass of a Magellanic Cloud planetary nebula by speckle interferometry.
Barlow, M. J.; Morgan, B. L.; Standley, C. +1 more
A Magellanic Cloud planetary nebula is resolved by speckle interferometry for the first time. The observations of SMC N2 show it to have a double-ring structure, the rings having angular radii of 0.22 and 0.38 arcsec, corresponding to absolute radii of 0.06 and 0.10 pc. The speckle observations of the galactic planetary nebula Vy 2-2 show a ring o…
Circumstellar envelope around the binary system lambda And.
Glebocki, R.; Sikorski, J.; Bielicz, E. +1 more
Asymmetries in emission peaks and relative shifts of h3 and k3 absorptions in Mg II resonant lines are analysed in 31 spectra of λ And (long period RS CVn type star) obtained in the years 1978 - 1983. An evident correlation is found between these values and the orbital phase. The only reasonable explanation of this correlation is the existence of …
Autoionizing levels in Si II and identification of the 1400 Å feature of Ap-Si stars.
Artu, M. -C.
The author reports four new high energy levels of Si II belonging to the core-excited terms 3s3p(1P)3d2D0 and 2P0. They are determined from the classification of six laboratory UV emission lines. A broadening due to autoionization is detected for two of them. These results fix the energy of th…
Spectrum and Chemical Analysis of the Double-Ring Planetary Nebula IC 1297
Feibelman, Walter A.; Aller, Lawrence H.; Keyes, Charles D.
The double-ring planetary nebula IC 1297 resembles NGC 7662 in appearance, although it is of much lower surface brightness. What is remarkable is the great strength of the dielectronic recombination O V line. Although this line is seen as a P Cygni feature in a number of planetary nebulae, it is in those instances accompanied by a strong continuum…
New X-Ray and Optical Observations of the X-Ray Discovered QSO-Galaxy Pair 1E 0104.2+3153
Stocke, J. T.; Giommi, P.; Maccacaro, T. +2 more
New X-ray and optical observations are presented of the QSO-galaxy pair 1E 0104.2 + 3153, originally discovered as a serendipitous source in the Einstein Observatory Medium Sensitivity Survey (Gioia et al., 1984). Results from an extremely deep Exosat observation are used to suggest that the QSO rather than the compact group of galaxies is the opt…
Analysis of the ultraviolet spectrum (2000 A to 3000 A) of Vega.
Sadakane, K.; Hirata, R.; Nishimura, M.
A high-dispersion spectrum of Vega between 2000 and 3000 A is analyzed. The continuum level is determined by searching for line-free windows, comparing the observed spectrum with a synthesized one. The damping constant of the Fe II lines arising from low-excitation levels is found to be very close to the classical value. The microturbulence parame…
The properties of the nuclei of the two hot SPOT galaxies NGC 1097 and 2997.
Walsh, J. R.; Nandy, K.; Meaburn, J. +1 more
NGC 1097 and 2997 are barred-spiral galaxies with hot spots in annuli around their central red nuclei. IUE low-dispersion spectra of two hot spots in NGC 1097 and of the ensemble of knots in the annulus around the central nucleus of NGC 2997 are presented. In addition, low-dispersion visible spectra of the hot spots and nuclei of both galaxies are…
IUE Observations of Accretion Columns in Two Zeta Aurigae--Type Systems
Ahmad, I. A.
This paper reports the existence of an accretion column in 32 Cyg. It also confirms the presence of the accretion column in ζ Aur and reports the detection of secular variations. Mg II observations support the parameters derived by Ahmad, Chapman, and Kondo for ζ Aur but suggest that the column may be curved. A C IV and Si IV emission component is…
Implications of the light curve of the A-type W UMa binary V566 Ophiuchi.
Eaton, Joel A.
Broadband (2585-3200-A) IUE photometric observations of V566 Oph obtained in three 8-h shifts on July 17-19, 1984 are reported and solved simultaneously with the ground-based optical observations of Bookmyer (1976). The observed light curves are fit to theoretical Roche-model light curves using the computer program described by Eaton (1986). The d…
Ultraviolet Survey for Hot Companions among Nonvariable Yellow Supergiants
Arellano Ferro, A.; Madore, B. F.
Twenty nonvariable yellow supergiants have been observed for the first time with the International Ultraviolet Explorer satellite, with the aim of discovering hot companions. Two newly discovered systems are announced: HD 74395 (G2 I + B9.5 IV-V) and HD 193469 (later than G0 + B8 IV-V). The Cepheid HD 9250 was also observed, but no hot companion w…