Results 81 to 90 of about 335 (184)
The Bowen Fluorescence Mechanism in Planetary Nebulae and Seyfert Galaxy Nuclei
, 1969 The efficiency of the Bowen fluorescence mechanism in models of planetary nebulae and Seyfert galaxy nuclei has been calculated by solving the equation of transfer for He II Ly -o( and the Bowen lines using the Feautrier method.
Williams, R. E., Weymann, R. J.
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On the mass loss rate by the nuclei of planetary nebulae
, 1986 Предложен вид зависимости скорости расширения планетарной туманности от ее линейных размеров Vs(Rs), хорошо описывающей наблюдаемый характер поведения скоростей расширения оболочек ПТ.
Кроль, В.А.
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New Close Binary Central Stars of Planetary Nebulae from Gaia DR3 Epoch Photometry. [PDF]
Res Notes AAS, 2022 Chornay N, Walton NA.
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Close Binary (and Pulsating) Nuclei of Planetary Nebulae [PDF]
International Astronomical Union Colloquium, 1979 Close-binary central stars of planetary nebulae are of interest to participants in this Colloquium because of recent suggestions that the cataclysmic binaries, containing a white dwarf and a lower-main-sequence star, may be descended from such objects (e.g.
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Hot planetary nebulae nuclei and related objects
, 1995 The hottest central stars found in planetary nebulae excite the O VI atomic transition in their atmospheres. Presumably the central stars of all planetary nebulae become O VI stars during some phase of their evolution. Observational studies show that all
Stanghellini, Letizia
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A Method of Determination of the Temperature of Nuclei of the Planetary Nebulae [PDF]
Symposium - International Astronomical Union, 1968 I would like to make a few comments on the problem of the determination of the temperatures of nuclei of planetary nebulae.It can be shown that in a high-excitation planetary nebula two independent Strömgren zones of heavy elements can be found. The first is a He III zone; the second corresponds to a zone of the luminescence of Ne V forbidden lines and
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A Search for Cool Companions of Planetary Nebula Nuclei [PDF]
Symposium - International Astronomical Union, 1989 At present only a small number of planetary nebulae are known to possess binary nuclei. Since approximately 2/3 of main sequence stars are members of binary or multiple star systems, one might expect a large fraction of PN central stars to have gravitationally bound companions.
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Nuclei of Planetary Nebulae in the Pulsation Instability Strip [PDF]
International Astronomical Union Colloquium, 1977 Pulsation properties of relevant stellar models are investigated with the linear nonadiabatic method. Short-period variability of FG Sge is interpreted as a pulsation phenomenon.
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Fast, low-ionization emission regions and other microstructures in planetary nebulae
, 1993 Planetary nebulae (PNs) have highly articulated structures, called "microstructures", little of which has been explored with spectrophotometry at high spatial resolution.
Chengalur, Jayaram N. +3 more
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The Temperatures of the Nuclei of Planetary Nebulae [PDF]
Monthly Notices of the Royal Astronomical Society, 1933 R. H. Stoy, A. Eddington
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