scholarly journals A radial velocity survey for post-common-envelope Wolf–Rayet central stars of planetary nebulae: first results and discovery of the close binary nucleus of NGC 5189★

2015 ◽  
Vol 448 (2) ◽  
pp. 1789-1806 ◽  
Author(s):  
Rajeev Manick ◽  
Brent Miszalski ◽  
Vanessa McBride
Keyword(s):  
Radial Velocity ◽  
Planetary Nebulae ◽  
Close Binary ◽  
Common Envelope ◽  
First Results ◽  
Central Stars

Imaging and spectroscopy of ejected common envelopes

1997 ◽  
Vol 180 ◽  
pp. 271-271
Author(s):  
D. L. Pollacco ◽  
S. A. Bell
Keyword(s):  
Electron Temperature ◽  
Planetary Nebulae ◽  
Temperature Fluctuations ◽  
Close Binary ◽  
Common Envelope ◽  
Recent Phase ◽  
Imaging And Spectroscopy ◽  
Central Stars

Imaging and spectroscopy are presented for four planetary nebulae known to contain close binary central stars resulting from a recent phase of common envelope evolution. These objects are Abell 41, Abell 46, Abell 63 and Abell 65. Determinations of the nebula abundances show that He is significantly enhanced in all of the objects. These results are in agreement with theoretical expectations. Uncertainties in the nebular electron temperature constrain other abundances less well. The line fluxes indicate that N is unexpectedly under-abundant. This effect is probably not real and may be an artifact of electron temperature fluctuations within the nebulae.

scholarly journals Precataclysmic Binaries in the Centre of Planetary Nebulae

1993 ◽  
Vol 155 ◽  
pp. 396-396
Author(s):  
G. Jasniewicz ◽  
A. Acker
Keyword(s):  
Planetary Nebulae ◽  
Central Star ◽  
Close Binary ◽  
Third Body ◽  
Common Envelope ◽  
Triple Star ◽  
Central Stars

We report at first on two old and large planetary nebulae (PN) of which central stars could satisfy the Ritter's criteria (1986) for being precataclysmic binaries: LoTr5 and Abell 35. Both nebulae have probably been ejected as a consequence of common-envelope evolution. A model of cataclysmic binary (CB) for the central star of Abell 35 has been tentatively attempted by Acker and Jasniewicz (1990). The nucleus of LoTr5 is a triple star (Jasniewicz et al., 1987; Malasan et al., 1991): action of a third body on the separation of the close binary could make this binary evolve into a CB (see Mazeh and Shaham, 1979). We report at second on the similarity between the spectrum of the central star of the extended PN HFG1 with that of a CB (Acker and Stenholm, 1990). The PN cited above could be fundamental objects just at the transition between the stage PN and the stage CB.

scholarly journals Surveying Planetary Nebulae Central Stars for Close Binaries: Constraining Evolution of Central Stars Based on Binary Parameters

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 85 ◽  
Author(s):  
Todd Hillwig
Keyword(s):  
Binary Stars ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Close Binary ◽  
Close Binaries ◽  
Common Envelope ◽  
Close Binary Stars ◽  
Red Giant ◽  
The Relationship ◽  
Central Stars

The increase in discovered close binary central stars of planetary nebulae is leading to a sufficiently large sample to begin to make broader conclusions about the effect of close binary stars on common envelope evolution and planetary nebula formation. Herein I review some of the recent results and conclusions specifically relating close binary central stars to nebular shaping, common envelope evolution off the red giant branch, and the total binary fraction and double degenerate fraction of central stars. Finally, I use parameters of known binary central stars to explore the relationship between the proto-planetary nebula and planetary nebula stages, demonstrating that the known proto-planetary nebulae are not the precursors of planetary nebulae with close binary central stars.

scholarly journals Close Binary (and Pulsating) Nuclei of Planetary Nebulae

1979 ◽  
Vol 53 ◽  
pp. 266-268
Author(s):  
Howard E. Bond
Keyword(s):  
Angular Momentum ◽  
White Dwarf ◽  
Main Sequence ◽  
Planetary Nebulae ◽  
Close Binary ◽  
Common Envelope ◽  
Secondary Star ◽  
Cataclysmic Binaries ◽  
Red Giant ◽  
Central Stars

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. Paczynski 1976; Ritter 1976; Webbink 1978; Meyer and Meyer-Hofmeister 1978; Livio, Salzman, and Shaviv 1979). The proposed scenario is. that a binary system of initially large separation (P.= 1-10 yr) forms a “common-envelope” binary after the primary has evolved to the red-giant stage and developed a degenerate core. The secondary star spirals inward inside the red-giant envelope, eventually transferring enough angular momentum to the envelope to eject it. The result is a close binary containing the hot degenerate core of the red giant and a cool main-sequence companion, surrounded by the ejected envelope, which is ionized by the hotter star. Much later, when the cool companion begins to evolve, it will start to transfer matter to the hot star (by now a white dwarf), and cataclysmic activity ensues.

scholarly journals Planetary Nebulae by Binary Nuclei

1993 ◽  
Vol 155 ◽  
pp. 279-290 ◽  
Author(s):  
Mario Livio
Keyword(s):  
Binary Systems ◽  
Planetary Nebulae ◽  
Close Binary ◽  
Common Envelope ◽  
The Common ◽  
Source Of Information ◽  
Central Stars

Planetary nebulae with close binary nuclei are reviewed. It is shown that these systems can be used as a source of information for the physics of the common envelope phase in the evolution of binary systems. Mechanisms for the production of bipolar planetary nebulae are examined and it is concluded that presently the action of binary companions to the central stars appears to provide the most promising mechanism. Other systems (e.g. novae, supernovae) in which similar processes may be operating are discussed.

scholarly journals Imaging the elusive H-poor gas in planetary nebulae with large abundance discrepancy factors

2016 ◽  
Vol 12 (S323) ◽  
pp. 65-69 ◽  
Author(s):  
Jorge García-Rojas ◽  
Romano L. M. Corradi ◽  
Henri M. J. Boffin ◽  
Hektor Monteiro ◽  
David Jones ◽  
...  
Keyword(s):  
Planetary Nebulae ◽  
Tunable Filter ◽  
Close Binary ◽  
Chemical Abundances ◽  
Dual Nature ◽  
Gas Phases ◽  
Binary Evolution ◽  
The Universe ◽  
Central Stars

AbstractThe discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited lines (CELs) is a major, unresolved problem with significant implications for the determination of chemical abundances throughout the Universe. In planetary nebulae (PNe), the most common explanation for the discrepancy is that two different gas phases coexist: a hot component with standard metallicity, and a much colder plasma enhanced in heavy elements. This dual nature is not predicted by mass loss theories, and direct observational support for it is still weak. In this work, we present our recent findings that demonstrate that the largest abundance discrepancies are associated with close binary central stars. OSIRIS-GTC tunable filter imaging of the faint O ii ORLs and MUSE-VLT deep 2D spectrophotometry confirm that O ii ORL emission is more centrally concentrated than that of [Oiii] CELs and, therefore, that the abundance discrepancy may be closely linked to binary evolution.

scholarly journals Planetary Nebulae Embryo after a Common Envelope Event

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 75 ◽  
Author(s):  
Natalia Ivanova ◽  
Jose Nandez
Keyword(s):  
Binary Stars ◽  
Planetary Nebulae ◽  
Close Binary ◽  
Common Envelope ◽  
Characteristic Speed ◽  
Close Binary Stars

In the centers of some planetary nebulae are found close binary stars. The formation of those planetary nebulae was likely through a common envelope event, which transformed an initially-wide progenitor binary into the currently observed close binary, while stripping the outer layers away. A common envelope event proceeds through several qualitatively different stages, each of which ejects matter at its own characteristic speed, and with a different degree of symmetry. Here, we present how typical post-common envelope ejecta looks kinematically a few years after the start of a common envelope event. We also show some asymmetric features we have detected in our simulations (jet-like structures, lobes, and hemispheres).

scholarly journals Central Stars of Young Planetary Nebulae - A New Class of Variables

2003 ◽  
Vol 209 ◽  
pp. 237-238 ◽  
Author(s):  
G. Handler
Keyword(s):  
Mass Loss ◽  
Radial Velocity ◽  
Time Scales ◽  
Variable Star ◽  
Planetary Nebulae ◽  
Stellar Mass ◽  
New Class ◽  
Stellar Pulsation ◽  
Stellar Pulsations ◽  
Central Stars

A new class of variable star is proposed. These are variable central stars of young Planetary Nebulae exhibiting roughly sinusoidal (semi)regular photometric and/or radial velocity variations with time scales of several hours. Fourteen of these objects have been identified. Their temperatures are between 25000 and 50000 K and most show hydrogen-rich spectra. The most likely reason for the variability is stellar pulsation. Another possibility would be variable stellar mass loss, but in that case the mechansism causing it must be different from that operating in massive O stars. We speculate that it actually is the stellar pulsations which cause mass loss mdulations.

scholarly journals Spectrophotometric studies of Planetary Nebulae with [WR] central stars

1997 ◽  
Vol 180 ◽  
pp. 269-269
Author(s):  
M. Peña ◽  
G. Stasińska ◽  
C. Esteban ◽  
R. Kingsburgh ◽  
L. Koesterke ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Field ◽  
Planetary Nebulae ◽  
Model Atmosphere ◽  
The Other ◽  
Self Consistent ◽  
First Results ◽  
Photoionization Model ◽  
Central Stars

We present the first results of a project on PNe with [WR] nuclei whose aim is twofold. One is to search for possible spatial abundance variations inside the nebula. The other is to check whether, for each object, one can build a self-consistent photoionization model (with the code PHOTO, Stasińska 1990, A&AS, 83, 501) using, as an input, the ionizing radiation field from an expanding model atmosphere reproducing the observed stellar lines of He, C and O (Koesterke et al., these proceedings).

scholarly journals A survey for hot central stars of planetary nebulae – I. Methods and first results

2016 ◽  
Vol 465 (1) ◽  
pp. 293-301
Author(s):  
Graham C. Kanarek ◽  
Michael M. Shara ◽  
Jacqueline K. Faherty ◽  
David Zurek ◽  
Anthony F. J. Moffat
Keyword(s):  
Planetary Nebulae ◽  
First Results ◽  
Central Stars
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