scholarly journals Catalogue of the central stars of planetary nebulae

2020 ◽  
Vol 640 ◽  
pp. A10
Author(s):  
W. A. Weidmann ◽  
M. B. Mari ◽  
E. O. Schmidt ◽  
G. Gaspar ◽  
M. M. Miller Bertolami ◽  
...  

Planetary nebulae represent a potential late stage of stellar evolution, however, their central stars (CSPNe) are relatively faint and, therefore, pertinent information is available for merely < 20% of the Galactic sample. Consequently, the literature was surveyed to construct a new catalogue of 620 CSPNe featuring important spectral classifications and information. The catalogue supersedes the existing iteration by 25% and includes physical parameters such as luminosity, surface gravity, temperature, magnitude estimates, and references for published spectra. The marked statistical improvement enabled the following pertinent conclusions to be determined: the H-rich/H-poor ratio is 2:1, there is a deficiency of CSPNe with types [WC 5-6], and nearly 80% of binary central stars belong to the H-rich group. The last finding suggests that evolutionary scenarios leading to the formation of binary central stars interfere with the conditions required for the formation of H-poor CSPN. Approximately 50% of the sample with derived values of log L⋆, log Teff, and log g, exhibit masses and ages consistent with single stellar evolutionary models. The implication is that single stars are indeed able to form planetary nebulae. Moreover, it is shown that H-poor CSPNe are formed by higher mass progenitors. The catalogue is available through the Vizier database.

2020 ◽  
Vol 642 ◽  
pp. A71
Author(s):  
Marcin Hajduk

We obtained new spectra of fourteen Magellanic Cloud planetary nebulae with the South African Large Telescope to determine heating rates of their central stars and to verify evolutionary models of post-asymptotic giant branch stars. We compared new spectra with observations made in previous years. Five planetary nebulae showed an increase in excitation over time. Four of their central stars exhibit [WC] features in their spectra, including three new detections. This raises the total number of [WC] central stars of PNe in the Magellanic Clouds to ten. We compared determined heating rates of the four [WC] central stars with the He-burning post-asymptotic giant branch evolutionary tracks and the remaining star with the H-burning tracks. Determined heating rates are consistent with the evolutionary models for both H and He-burning post-asymptotic giant branch stars. The central stars of the PNe that show the fastest increase of excitation are also the most luminous in the sample. This indicates that [WC] central stars in the Magellanic Clouds evolve faster than H-burning central stars, and they originate from more massive progenitors.


1993 ◽  
Vol 153 ◽  
pp. 117-132
Author(s):  
G. Stasińska

After a discussion of the methods used to derive the physical parameters of planetary nebulae and their central stars, the global properties of planetary nebulae in the Galactic bulge are reviewed, and compared to those of planetary nebulae in different contexts.


1987 ◽  
Vol 320 ◽  
pp. 159 ◽  
Author(s):  
Lawrence H. Aller ◽  
Charles D. Keyes ◽  
Stephen P. Maran ◽  
Theodore R. Gull ◽  
Andrew G. Michalitsianos ◽  
...  

1988 ◽  
Vol 326 ◽  
pp. 1040
Author(s):  
Lawrence H. Aller ◽  
Charles D. Keyes ◽  
Stephen P. Maran ◽  
Theodore R. Gull ◽  
Andrew G. Michalitsianos ◽  
...  

1989 ◽  
Vol 131 ◽  
pp. 545-554
Author(s):  
James Liebert

Studies of hot white dwarf samples constrain the properties and evolution of planetary nuclei and the nebulae. In particular, the white dwarf and planetary nebulae formation rates are compared. I discuss the overlap of the sequences of white dwarfs having hydrogen (DA) and helium-rich (DO) atmospheres with known central stars of high surface gravity. There is evidence that the hydrogen atmosphere nuclei have “thick” outer hydrogen layers (≳ 10−4 M⊙), but that DA white dwarfs may have surface hydrogen layers orders of magnitude thinner. Finally, a DA planetary nucleus is discussed (0950+139) which has undergone a late nebular ejection; this object may be demonstrating that a hydrogen layer can be lost even after the star has entered the white dwarf cooling sequence.


1993 ◽  
Vol 155 ◽  
pp. 533-540 ◽  
Author(s):  
X. Hui ◽  
H.C. Ford

The study of extragalactic planetary nebulae has made rapid progress in recent years with the help of high quantum efficiency detectors. A brief but distinctive phase in the late stage of stellar evolution, planetary nebulae (PNe) are not only interesting objects in their own right, but also are extremely valuable and unique tools for probing the host galaxies. Recent studies have used planetary nebulae as test particles to investigate the dynamics and mass distributions in the halos of early type galaxies.


2020 ◽  
Vol 496 (1) ◽  
pp. 814-831
Author(s):  
Rahul Bandyopadhyay ◽  
Ramkrishna Das ◽  
Soumen Mondal ◽  
Samrat Ghosh

ABSTRACT We present results of our study of two planetary nebulae (PNe), PB1 and PC 19. We use the optical spectra of these two PNe observed at 2 m Himalayan Chandra Telescope and also archival and literature data for the study. We use the morphokinematic code shape to construct 3D morphologies of the PNe and the photoionization code cloudy to model the observed spectra. The 3D model of PB 1 consists of an elongated shell surrounded by a bipolar halo and that of PC 19 consists of an open lobed bipolar structure and a spiral filamentary pair. We analyse the ionization structure of the PNe by deriving several plasma parameters and by photoionization modelling. We estimate the elemental abundances of the elements, He, C, N, O, Ne, S, Ar, and Cl, from our analysis. We find He, C, and N abundances to be significantly higher in case of PB 1. We estimate different physical parameters of the central stars, namely effective temperature, luminosity, and gravity, and of the nebula, namely hydrogen density profiles, radii, etc., from photoionization modelling. We estimate distances to the PNe as ∼4.3 kpc for PB 1 and as ∼5.6 kpc for PC 19 by fitting the photoionization models to absolute observed fluxes. Progenitor masses are estimated from theoretical evolutionary trajectories and are found to be ∼1.67 and ∼2.38 M⊙ for PB 1 and PC 19, respectively.


2003 ◽  
Vol 209 ◽  
pp. 113-120 ◽  
Author(s):  
Bruce J. Hrivnak

The study of proto-planetary nebulae (PPNs) leads to a better understanding of both the preceding asymptotic giant branch and the succeeding planetary nebula phases of stellar evolution. Recent results are reviewed, emphasizing the properties of the central stars and the shape and chemistry of the nebulae. The study of PPNs is seen to be important in its own right.


1968 ◽  
Vol 34 ◽  
pp. 359-375
Author(s):  
C.R. O'Dell

The greatest activity in the area of evolution of the central stars of the planetary nebulae has occurred in the last two decades, although there have been significant contributions by many workers of considerable insight ever since the early studies at the Lick Observatory demonstrated the physical nature of this class of nebula. We shall try to draw together here the many facets of the present picture of this rapidly developing and highly significant phase of stellar evolution. Unfortunately, the picture is not at all as complete as one would like, and there remain several points of scientific contention; however, we should like to present the results of several investigators. A certain amount of redundancy with previous papers given prior will be necessary, but we shall endeavor to treat these topics briefly and in the context of the evolution of the nebulae and their stars.


1997 ◽  
Vol 180 ◽  
pp. 412-412
Author(s):  
M. Parthasarathy ◽  
A. Acker ◽  
D. de Martino ◽  
J. Koeppen ◽  
W. Leindecker

Hb 7 (003.9 - 14.9) and Sp 3 (342.5 - 14.3) are high galactic latitude planetary nebulae. Ultraviolet spectra obtained with the IUE reveal UV stellar continuum and P - Cygni stellar wind profiles of NV and CIV indicating post-AGB mass loss from the central stars of these two PN. From an analysis of optical and ultraviolet spectra we have derived the parameters of the central stars and nebulae. The IUE ultaviolet continuum shows that the central stars of Hb 7 and Sp3 are 08 stars. The Si IV 1400A doublet in the spectra of both these stars is very weak or absent most likely due to underabundance of Si and due to also due to earlier spectral type (O 8). The Si IV lines in hot stars are sensitive to surface gravity, their weakness suggests that surface gravity the central stars of Hb7 and Sp3 is relatively higher. The terminal velocity of the stellar wind in Hb7 and Sp 3 are found to be −2460 km/sec and −3630 km/sec respectively.


Sign in / Sign up

Export Citation Format

Share Document