Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity

Making use of the results from recent infrared and radio surveys of planetary nebulae, we have selected 431 nebulae to form a sample where a number of distance-independent parameters (e.g., Tb, Td, I60μm and IRE) can be constructed. In addition, we also made use of other distance-independent parameters ne and T∗ where recent measurements are available. We have investigated the relationships among these parameters in the context of a coupled evolution model of the nebula and the central star. We find that most of the observed data in fact lie within the area covered by the model tracks, therefore lending strong support to the correctness of the model. Most interestingly, we find that the evolutionary tracks for nebulae with central stars of different core masses can be separated in a Tb-T∗ plane. This implies that the core masses and ages of the central stars can be determined completely independent of distance assumptions. The core masses and ages have been obtained for 302 central stars with previously determined central-star temperatures. We find that the mass distribution of the central stars strongly peaks at 0.6 M⊙, with 66% of the sample having masses <0.64 MM⊙. The luminosities of the central stars are then derived from their positions in the HR diagram according to their core masses and central star temperatures. If this method of mass (and luminosity) determination turns out to be accurate, we can bypass the extremely unreliable estimates for distances, and will be able to derive other physical properties of planetary nebulae.

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The Remarkable Evolution of the Post-Agb Star FG SGE

Highlights of Astronomy ◽

10.1017/s1539299600021134 ◽

1998 ◽

Vol 11 (1) ◽

pp. 363-363

Author(s):

Johanna Jurcsik ◽

Benjamin Montesinos

Keyword(s):

Time Scales ◽

Effective Temperature ◽

Planetary Nebula ◽

Planetary Nebulae ◽

Central Star ◽

Evolutionary Models ◽

Single Star ◽

Line Intensities ◽

Evolutionary Changes ◽

Evolutionary Studies

FG Sagittae is one of the most important key objects of post-AGB stellar evolutionary studies. As a consequence of a final helium shell flash, this unique variable has shown real evolutionary changes on human time scales during this century. The observational history was reviewed in comparison with predictions from evolutionary models. The central star of the old planetary nebula (Hel-5) evolved from left to right in the HR diagram, going in just hundred years from the hot region of exciting sources of planetary nebulae to the cool red supergiant domain just before our eyes becoming a newly-born post-AGB star. The effective temperature of the star was around 50,000 K at the beginning of this century, and the last estimates in the late 1980s give 5,000-6,500 K. Recent spectroscopic observations obtained by Ingemar Lundström show definite changes in the nebular line intensities. This fact undoubtedly rules out the possibility that, instead of FG Sge, a hidden hot object would be the true central star of the nebula. Consequently, the observed evolutionary changes are connected with the evolution of a single star.

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Chemical Enrichment and Central Star Properties

Symposium - International Astronomical Union ◽

10.1017/s0074180900172468 ◽

1993 ◽

Vol 155 ◽

pp. 572-572

Author(s):

C.Y. Zhang

Keyword(s):

Planetary Nebulae ◽

Central Star ◽

Agb Stars ◽

Physical Processes ◽

Chemical Abundances ◽

Core Mass ◽

Chemical Enrichment ◽

The Core ◽

Stellar Temperature ◽

Independent Parameters

We have selected a sample of planetary nebulae, for which the core masses are determined using distance-independent parameters (Zhang and Kwok 1992). The chemical abundances of He, N, O, and C are taken from the literature for them. Relationships of the ratios of He/H, N/O, and C/O with various stellar parameters of planetary nebulae (PN), such as the core mass, the mass of the core plus the ionized nebular gas, the stellar age and temperature, are examined. It is found that the N/O increases with increasing mass, while the C/O first increases and then decreases with the core mass. No strong correlation seems to exist between the He/H and the core mass. A correlation of the N/O and He/H with the stellar temperature exists. The current dredge-up theory for the progenitor AGB stars cannot satisfactorily account for these patterns of chemical enrichment in PN. Furthermore, the correlations of the N/O and He/H with the stellar age and temperature indicate that besides the dredge-ups in the RG and AGB stages, physical processes that happen in the planetary nebula stage may also play a role in forming the observed patterns of chemical enrichment in the planetary nebulae.

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Characterizing global expansion evolution of the ionized matter in planetary nebulae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317001879 ◽

2016 ◽

Vol 12 (S323) ◽

pp. 352-353

Author(s):

J. A. López ◽

M. G. Richer ◽

M. Pereyra ◽

M. T. García-Díaz

Keyword(s):

Galactic Halo ◽

Evolutionary Rate ◽

Planetary Nebulae ◽

Central Star ◽

Global Expansion ◽

Kinematic Evolution ◽

Wide Range ◽

Model Predictions ◽

First Time ◽

Highly Evolved

AbstractBulk outflow or global expansion velocities are presented for a large number of planetary nebulae (PNe) that span a wide range of evolutionary stages and different stellar populations. The sample comprises 133 PNe from the Galactic bulge, 100 mature and highly evolved PNe from the disk, 11 PNe from the Galactic halo and 15 PNe with very low central star masses and low metallicities, for a total of 259 PNe. These results reveal from a statistical perspective the kinematic evolution of the expansion velocities of PNe in relation to changing characteristics of the central star’s wind and ionizing luminosity and as a function of the evolutionary rate determined by the central (CS) mass. The large number of PNe utilized in this work for each group of PNe under study and the homogeneity of the data provide for the first time a solid benchmark form observations for model predictions, as has been described by López et al. (2016).

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A consolidated online database of Galactic planetary nebulae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312011830 ◽

2011 ◽

Vol 7 (S283) ◽

pp. 442-443

Author(s):

Brent Miszalski ◽

A. Acker ◽

F. Ochsenbein ◽

Q. A. Parker

Keyword(s):

Planetary Nebulae ◽

Central Star ◽

Radial Velocities ◽

Online Database ◽

Line Intensities ◽

Multi Wavelength

AbstractSince the issue of the unifying Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (SECGPN) a large number of new discoveries have been made thanks to improved surveys and discovery techniques. The increasingly heterogeneous published population of Galactic PNe, that we have determined totals <2850 PNe, is becoming more difficult to study on the whole without a centralised repository. We introduce a consolidated and interactive online database with object classifications that reflect the latest multi-wavelength data and the most recent results. The extensible database, hosted by the Centre de Donnees astronomique de Strasbourg (CDS), will contain a wealth of observed data for large, well-defined samples of PNe including coordinates, multi-wavelength images, spectroscopy, line intensities, radial velocities and central star information. It is anticipated that the database will be publicly released early 2012.

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Central Star and Nebular Masses for Magellanic Cloud Planetary Nebulae

Symposium - International Astronomical Union ◽

10.1017/s0074180900138744 ◽

1989 ◽

Vol 131 ◽

pp. 355-355 ◽

Cited By ~ 1

Author(s):

D. J. Monk ◽

M. J. Barlow ◽

R. E. S. Clegg

Keyword(s):

Planetary Nebulae ◽

Central Star ◽

Magellanic Cloud ◽

Effective Temperatures ◽

Central Stars

AAT and IUE spectra of thirteen medium-excitation Magellanic Cloud planetary nebulae have been used to derive H I Zanstra effective temperatures and surface gravities for the central stars.

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Searching for central stars of planetary nebulae in Gaia DR2

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037554 ◽

2020 ◽

Vol 638 ◽

pp. A103 ◽

Cited By ~ 3

Author(s):

N. Chornay ◽

N. A. Walton

Keyword(s):

Planetary Nebulae ◽

Central Star ◽

Ratio Method ◽

Distance Measurements ◽

Accurate Identification ◽

Trigonometric Parallaxes ◽

Model Independent ◽

Statistical Distance ◽

Automated Technique ◽

Central Stars

Context. Accurate distance measurements are fundamental to the study of planetary nebulae (PNe) but they have long been elusive. The most accurate and model-independent distance measurements for galactic PNe come from the trigonometric parallaxes of their central stars, which were only available for a few tens of objects prior to the Gaia mission. Aims. The accurate identification of PN central stars in the Gaia source catalogues is a critical prerequisite for leveraging the unprecedented scope and precision of the trigonometric parallaxes measured by Gaia. Our aim is to build a complete sample of PN central star detections with minimal contamination. Methods. We developed and applied an automated technique based on the likelihood ratio method to match candidate central stars in Gaia Data Release 2 (DR2) to known PNe in the Hong Kong/AAO/Strasbourg Hα PN catalogue, taking into account the BP – RP colours of the Gaia sources as well as their positional offsets from the nebula centres. These parameter distributions for both true central stars and background sources were inferred directly from the data. Results. We present a catalogue of over 1000 Gaia sources that our method has automatically identified as likely PN central stars. We demonstrate how the best matches enable us to trace nebula and central star evolution and to validate existing statistical distance scales, and we discuss the prospects for further refinement of the matching based on additional data. We also compare the accuracy of our catalogue to that of previous works.

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The Evidence for Planetary Progenitor Rotation and for the Long Term Acceleration of the Ejected Nebular Shell

International Astronomical Union Colloquium ◽

10.1017/s0252921100081926 ◽

1980 ◽

Vol 58 ◽

pp. 467-472

Author(s):

Ronald C. Kirkpatrick

Keyword(s):

Ionizing Radiation ◽

Planetary Nebulae ◽

Central Star ◽

Theoretical Studies ◽

Significant Period

Abstract:Several theories seek to explain the peculiar shapes of planetary nebulae. Those of Louise, Kirkpatrick, and Phillips and Reay rely on progenitor rotation. The velocity-radius relation for the shells of well observed planetaries do not extrapolate back through the origin, but rather fall short, suggesting that the shell acquires its velocity over a significant period of time. Kirkpatrick’s theory relies heavily on long term acceleration of the nebular shell, and other theoretical studies support the idea of acceleration of the nebular shell up to the time it becomes optically thin to the ionizing radiation from the central star.

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The Edinburgh/AAO/Strasbourg Catalogue of Galactic Planetary Nebulae

Symposium - International Astronomical Union ◽

10.1017/s0074180900207985 ◽

2003 ◽

Vol 209 ◽

pp. 41-41 ◽

Cited By ~ 2

Author(s):

Q. A. Parker ◽

M. Hartley ◽

D. Russeil ◽

A. Acker ◽

F. Ochsenbein ◽

...

Keyword(s):

Galactic Plane ◽

Angular Size ◽

Planetary Nebulae ◽

Depth Resolution ◽

Central Star ◽

Isolation And Identification ◽

Large Numbers ◽

Low Surface Brightness ◽

Bulge Region ◽

Version 2.0

We report on version 1.0 of the Edinburgh/AAO/Strasbourg catalogue of new and possible Planetary Nebulae (PN) distributed via cdrom at this meeting. We provide accurate positions, designations, images and other descriptive parameters for the PN. In future releases this will be supplemented by inclusion of spectra and related material such as line ratios, velocities etc.The 900+ PN have been discovered solely from visual scrutiny of narrow-band exposures taken for the AAO/UKST H-alpha survey of the Southern Galactic Plane. Most have classic PN-type morphologies (i.e. bi-polar, rings, shells or ovals). SuperCOSMOS data will soon supersede our visual scanning but it proved an effective preliminary technique to identify candidate PN on the basis of morphology, isolation and identification as an H-alpha nebulosity. We already have confirmatory spectroscopy for ~ 700 objects. Much of our new sample are of very low surface brightness, with no obvious central star, and so have remained undetected in previous surveys. They are revealed here due to the excellent depth, resolution, coverage and uniformity of the H-alpha survey. Many PN are also well extended. The average angular size is 51″ with the median of 27″ but examples extend to several arcminutes. This may indicate many are in a highly evolved state where the central star has faded from easy optical detection and the nebula itself is dissipating into the ambient ISM. Large numbers of candidate PN have also been found in the Galactic Bulge region, most of which have been confirmed via UKST FLAIR/6dF MOS spectroscopy (Parker et al, in preparation and these proceedings).By version 2.0 (release in 2002) we will have doubled the number of Galactic PN accrued from all sources over the last 75 years. This new catalogue should have a profound impact on many aspects of PN research.

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Models of Planetary Nebulae: Generalisation of the Multiple Winds Model

Symposium - International Astronomical Union ◽

10.1017/s0074180900138811 ◽

1989 ◽

Vol 131 ◽

pp. 411-424 ◽

Cited By ~ 5

Author(s):

F. D. Kahn

Keyword(s):

Planetary Nebula ◽

High Speed ◽

Planetary Nebulae ◽

Central Star ◽

Theoretical Description ◽

Basic Theory ◽

Spectral Lines ◽

High Excitation ◽

General Shape ◽

Fast Wind

According to the multiple winds model a planetary nebula forms as the result of the interaction of a fast wind from the central star with the superwind that had previously been emitted by the progenitor star. The basic theory which deals with the spherically symmetrical case is briefly summarised. Various improvements are then considered in turn. A better history is clearly needed of the way that the central star becomes hotter, it is unrealistic to make the assumption that the superwind is spherically symmetrical, and finally there are likely to be important instabilities at some of the interfaces in the PN, notably that between the shocked superwind and the HII layer. These changes in the theoretical description produce a better understanding of the conditions in the outer parts of a PN and of the nature of its general shape, and they should lead to an explanation for the occurrence of high speed motions, and of highly ionized species and high excitation spectral lines.

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