scholarly journals Search for envelopes of some stellar planetary nebulae, symbiotic stars and further emission-line objects

1997 ◽  
Vol 125 (3) ◽  
pp. 445-451 ◽  
Author(s):  
L. Kohoutek
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Symbiotic Stars

scholarly journals Broad Hα wings in Young Planetary Nebulae

2003 ◽  
Vol 209 ◽  
pp. 391-392
Author(s):  
Anabel Arrieta ◽  
Silvia Torres-Peimbert
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Symbiotic Stars ◽  
First Report

In a sample of 30 young planetary nebulae, proto-PNe and other emission line objects we have found 11 young PNe and 2 symbiotic stars that show very broad wings of the emission Hα line (from 800 km s-1 and up to 5100 km s-1). For 7 objects, their first report was in Arrieta & Torres-Peimbert (2002).

scholarly journals Is there Any Connection Between Planetary Nebulae and Symbiotic Stars ?

1993 ◽  
Vol 155 ◽  
pp. 401-401
Author(s):  
Michael Friedjung
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
H Ii Regions ◽  
Symbiotic Stars ◽  
Cool Star

Symbiotic stars have sometimes been misidentified as planetary nebulae, because their line spectra are similar to those of planetary nebulae particularly in the ultraviolet L.(Houziaux 1982 in “The Nature of Symbiotic Stars”, M. Friedjung & R. Viotti eds., Reidel. p 229), while the infrared shows the presence of the spectrum of a cool star. The similarity is not complete; when H. E. Schwarz (1988 in “The Symbiotic Phenomenon”, J. Mikolajewska et al eds., Kluwer, p 123) plotted a graph of two ratios derived from emission line fluxes, symbiotic stars did not occupy the regions of the diagram occupied by planetary nebulae and H II regions.

scholarly journals Peculiar Central Stars and Related Objects

1978 ◽  
Vol 76 ◽  
pp. 212-212
Author(s):  
Julie Lutz
Keyword(s):  
Emission Line ◽  
Absorption Spectra ◽  
Planetary Nebulae ◽  
Symbiotic Stars ◽  
Be Stars ◽  
Phase 3 ◽  
Emission Line Spectrum ◽  
Protoplanetary Nebula ◽  
Astronomy And Astrophysics ◽  
Central Stars

Results are presented of a spectroscopic survey of sixteen peculiar central stars (i.e., central stars which have absorption spectra and continuua which are too cool to account for the superimposed emission line spectrum). Classifications on the MK system are presented for the absorption spectra. Intensities relative to H are presented for some of the strongest emission lines. The relationships between peculiar central stars and other types of emission line objects such as Be stars, symbiotic stars and P Cygni stars will be discussed. Three interpretations for peculiar central stars will be considered: 1) Some of them are binary nuclei of planetary nebulae, 2) Some of them are manifestations of the protoplanetary nebula phase, 3) Some of them are not related to planetary nebulae. (Paper will appear in Astronomy and Astrophysics.)

scholarly journals Hybrid 3-D Spectrophotometry of Emission-Line Nebulae at Ohio State

1995 ◽  
Vol 149 ◽  
pp. 167-171
Author(s):  
Richard W. Pogge ◽  
Nancy Joanne Lame
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Hii Regions ◽  
Ohio State University ◽  
State University ◽  
Considerable Success ◽  
Fabry Perot ◽  
The Ohio State University ◽  
Scientific Results ◽  
Narrowband Filter

AbstractA program of 3-D spectrophotometry of emission nebulae being carried out at the Ohio State University will be described. We have had considerable success combining Fabry-Perot imaging, long-slit spectroscopy, and narrowband filter imaging into a hybrid 3-D spectroscopic approach that we have used to obtain detailed spectrophotometric maps of the density, temperature, extinction, and ionization in HII regions and Planetary Nebulae. The centerpiece instrument of this effort, the OSU Imaging Fabry-Perot Spectrograph (IFPS), will be described, and scientific results illustrative of our work will be presented.

scholarly journals Symbiotic stars and other Hα emission-line stars towards the Galactic bulge★

2013 ◽  
Vol 432 (4) ◽  
pp. 3186-3217 ◽  
Author(s):  
Brent Miszalski ◽  
Joanna Mikołajewska ◽  
Andrzej Udalski
Keyword(s):  
Emission Line ◽  
Symbiotic Stars ◽  
Galactic Bulge ◽  
Hα Emission

Diagnostic Diagrams for Planetary Nebulae and Symbiotic Stars

1993 ◽  
pp. 403-403
Author(s):  
A. Gutierrez-Moreno ◽  
H. Moreno ◽  
G. Cortes
Keyword(s):  
Planetary Nebulae ◽  
Symbiotic Stars

scholarly journals The Ionization of Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 190-204 ◽  
Author(s):  
Robert E. Williams
Keyword(s):  
Ionizing Radiation ◽  
Emission Line ◽  
Radiation Field ◽  
Planetary Nebulae ◽  
Model Atmosphere ◽  
Evolutionary Sequence ◽  
Lyman Continuum ◽  
The Mean ◽  
Central Stars

The ionization of the most abundant elements in planetary nebulae has been determined for a number of models of nebulae at different epochs in their expansion. The values used for the temperatures and radii of the central stars and the sizes and densities of the shells have come from Seaton's evolutionary sequence. The ionizing radiation field has been taken from model atmosphere calculations of the central stars by Gebbie and Seaton, and Böhm and Deinzer. Emission-line fluxes have been calculated for the models and compared with observations of planetary nebulae by O'Dell, Osterbrock's group, and Aller and his collaborators. Results indicate that the central stars have strong He+ Lyman continuum excesses, similar to those predicted by Gebbie and Seaton. The mean abundance determinations for the nebulae made by Aller are confirmed, with the exception of nitrogen, which appears to be 3 or 4 times more abundant than his value. It is also seen that the electron temperatures of the nebulae are higher than previous theoretical determinations, providing better agreement with empirically derived values.

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