scholarly journals Evolution of Magellanic Cloud Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 356-356
Author(s):  
Stephen J. Meatheringham ◽  
Michael A. Dopita ◽  
Peter R. Wood ◽  
B. Louise Webster ◽  
David H. Morgan ◽  
...  
Keyword(s):  
Total Energy ◽  
Density Gradient ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Expansion Velocity ◽  
Low Velocity ◽  
Tight Correlation

New evolutionary correlations have been discovered to apply to the population of Planetary Nebulae (FN) in the Magellanic Clouds. Firstly, the age of the nebular shell is found to follow a relationship τ = 890[(Mneb/M⊙) (Vexp/km s−1)]0,6 yr, which is shown to be consistent with a model in which the total energy of the ionised and swept up gas drives the expansion down the density gradient in the precursor AGE wind. Secondly, a tight correlation is found between the expansion velocity and a combination of the Excitation Class and the Hβ flux. This appears to be determined by the mass of the planetary nebula nuclear star. These correlations provide strong observational support for the idea that the PN shells are ejected at low velocity during the Asymptotic Giant Branch phase of evolution, and that they are continually accelerated during their nebular lifetimes.

scholarly journals Planetary Nebulae in the Magellanic Clouds: Probing Stellar Evolution and Populations

2003 ◽  
Vol 209 ◽  
pp. 567-574
Author(s):  
Letizia Stanghellini
Keyword(s):  
Stellar Evolution ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Field Of Study ◽  
Early Results

This review contains: (1) the scientific motivations for studying Planetary Nebulae in the Magellanic Clouds; (2) a review of this field of study, from the origins to the most recent results, focusing on the papers that have been published since the last IAU Symposium on Planetary Nebulae; (3) a review of the Hubble contribution to the field, from the early results to our own Magellanic Cloud Planetary Nebula program.

scholarly journals Binary interactions on the RGB: Dusty post-RGB stars

2016 ◽  
Vol 12 (S323) ◽  
pp. 223-226
Author(s):  
Devika Kamath ◽  
Hans Van Winckel ◽  
Peter Wood
Keyword(s):  
Radial Velocity ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Binary Interaction ◽  
Small Magellanic Cloud ◽  
Preliminary Results ◽  
Low Metallicity ◽  
Binary Evolution

AbstractIt is widely accepted that binary interactions are responsible for the shaping of planetary nebula. However, these binary interactions and evolutionary channels are poorly understood. Our recent study revealed a newly discovered population of low-luminosity, low-metallicity, likely binaries in the Magellanic Clouds: dusty post-RGB stars. They are likely to have evolved off the RGB via binary interaction. In this paper we present preliminary results of the first radial velocity monitoring of the post-RGB stars in the Small Magellanic Cloud (SMC) and the implications on stellar (binary) evolution. We also investigate their link, if any, to the planetary nebulae systems.

scholarly journals Planetary nebulae and Wolf-Rayet stars in the Magellanic Clouds

1964 ◽  
Vol 20 ◽  
pp. 316-321 ◽  
Author(s):  
B. E. Westerlund
Keyword(s):  
Planetary Nebula ◽  
Large Scale ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Small Magellanic Cloud ◽  
Solar Mass ◽  
The Masses

Objects in the Small Magellanic Cloud classified by Lindsay (1961) as planetary nebulae or probable planetary nebulae have been studied in detail on large-scale photographs (Henize and Westerlund 1963). Of Lindsay's 50 objects, 11 are clearly resolved, 2 are probably resolved, 12 show stellar images, 13 are below the limit of the plates, 11 (fairly faint) are outside the photographed regions, and 1 is of uncertain identification. The masses of the resolved nebulae lie between 2 and 33 solar masses. They are therefore classified as small diffuse nebulae; it appears unlikely that the mass of a planetary nebula can exceed a few tenths of a solar mass.

scholarly journals Planetary Nebulae in the Magellanic Clouds

1989 ◽  
Vol 131 ◽  
pp. 319-334 ◽  
Author(s):  
M. J. Barlow
Keyword(s):  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
The Past ◽  
Optical Telescopes

The past few years have seen the study of Magellanic Cloud planetary nebulae cease to be an extragalactic sideshow and instead become one of the most quantitative branches of planetary nebula research, due largely to our ability to fully exploit the known distances to these systems since the launch of IUE and the advent of sensitive digital detectors mounted on large optical telescopes.

scholarly journals Deduction of Planetary Nebulae Properties from Long Period Variable Precursors

1983 ◽  
Vol 103 ◽  
pp. 291-291
Author(s):  
M. S. Bessell ◽  
P. R. Wood
Keyword(s):  
Planetary Nebula ◽  
Mass Spectra ◽  
Planetary Nebulae ◽  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Long Period ◽  
Period Variable ◽  
Low Mass ◽  
Nucleus Mass

Infra-red (JHK) photometry of long period variables (LPV) in the Magellanic Clouds has shown that the LPV's can be divided into core helium burning supergiants and asymptotic giant branch (AGB) stars. Application of the pulsation theory allows masses to be derived for the LPV's while stellar evolution theory allows core masses to be derived for the AGB stars. By considering evolution of the LPV's in the (Mbol,P) diagram, estimates of planetary nebula mass and planetary nebula nucleus mass are derived as a function of initial mass. Spectra of the LPV's suggest that many low mass planetary nebulae in the Magellanic Clouds should be carbon rich while the more massive nebulae may be nitrogen enhanced.

scholarly journals Atomic hydrogen in the planetary nebula IC 4997

1987 ◽  
Vol 122 ◽  
pp. 501-502
Author(s):  
C. Giovanardi ◽  
D.R. Altschuler ◽  
S.E. Schneider ◽  
P.R. Silverglate
Keyword(s):  
Atomic Hydrogen ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Expansion Velocity ◽  
Hydrogen Emission

In the course of a sensitive search for atomic hydrogen emission associated with planetary nebulae having high velocities relative to Galactic HI (Schneider et al. 1986), we detected absorption in the spectrum of IC 4997 (PK 58-10.1). This is only the second definite detection of HI associated with a PN. The velocity of the feature coincides precisely with that expected if the gas is expanding with the measured optical expansion velocity of 14 km s−1 (Sabbadin 1984), strongly suggesting an association.

scholarly journals Surface magnetic activity of the fast-rotating G5 giant IN Comae, central star of the faint planetary nebula LoTr 5

2019 ◽  
Vol 624 ◽  
pp. A83 ◽  
Author(s):  
Zs. Kővári ◽  
K. G. Strassmeier ◽  
K. Oláh ◽  
L. Kriskovics ◽  
K. Vida ◽  
...  
Keyword(s):  
Time Series ◽  
Differential Rotation ◽  
Planetary Nebula ◽  
Spectral Synthesis ◽  
Binary Star ◽  
Rotation Period ◽  
Planetary Nebulae ◽  
Asymptotic Giant Branch ◽  
Stellar Surface ◽  
Average Lifetime

Context. On the asymptotic giant branch, low to intermediate mass stars blow away their outer envelopes, forming planetary nebulae. Dynamic interaction between the planetary nebula and its central progenitor is poorly understood. The interaction is even more complex when the central object is a binary star with a magnetically active component, as is the case for the target in this paper. Aims. We aim to quantify the stellar surface activity of the cool binary component of IN Com and aim to explain its origin. In general, we need a better understanding of how central binary stars in planetary nebulae evolve and how this evolution could develop such magnetically active stars as IN Com. Methods. We present a time series of 13 consecutive Doppler images covering six months in 2017 that we used to measure the surface differential rotation with a cross-correlation method. Hitherto unpublished high-precision photometric data from 1989 to 2017 are presented. We applied Fourier-transformation-based frequency analysis to both photometry and spectra. Very high resolution (R ≈ 200 000) spectra were used to update IN Com’s astrophysical parameters by means of spectral synthesis. Results. Our time-series Doppler images show cool and warm spots coexisting with an average surface temperature contrast of −1000 K and +300 K with respect to the effective temperature. Approximately 8% of the stellar surface is covered with cool spots and ∼3% with warm spots. A consistent cool polar spot is seen in all images. The average lifetime of the cool spots is not much more than a few stellar rotations (one month), while the warm spots appear to live longer (three months) and are mostly confined to high latitudes. We found anti-solar surface differential rotation with a shear coefficient of α = −0.026 ± 0.005 suggesting an equatorial rotation period of 5.973 ± 0.008 d. We reconfirm the 5.9 day rotation period of the cool star from photometry, radial velocities, and Hα line-profile variations. A long-term V-brightness variation with a likely period of 7.2 yr is also found. It appears in phase with the orbital radial velocity of the binary system in the sense that it is brightest at highest velocity and faintest at lowest velocity, that is, at the two phases of quadrature. We redetermine [Ba/Fe], [Y/Fe], and [Sr/Fe] ratios and confirm the overabundance of these s-process elements in the atmosphere of IN Com.

scholarly journals The morpho-kinematics of the circumstellar envelope around the AGB star EP Aqr

2019 ◽  
Vol 484 (2) ◽  
pp. 1865-1888 ◽  
Author(s):  
D T Hoai ◽  
P T Nhung ◽  
P Tuan-Anh ◽  
P Darriulat ◽  
P N Diep ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Loss Rate ◽  
Equatorial Region ◽  
Data Cube ◽  
Asymptotic Giant Branch ◽  
Expansion Velocity ◽  
Circumstellar Envelope ◽  
Low Velocity ◽  
Loss Mechanism ◽  
Asymptotic Giant Branch Star

ABSTRACT ALMA observations of CO(1–0) and CO(2–1) emissions of the circumstellar envelope of EP Aqr, an oxygen-rich asymptotic giant branch star, are reported. A thorough analysis of their properties is presented using an original method based on the separation of the data cube into a low-velocity component associated with an equatorial outflow and a faster component associated with a bipolar outflow. A number of important and new results are obtained concerning the distribution in space of the effective emissivity, the temperature, the density, and the flux of matter. A mass-loss rate of (1.6 ± 0.4)×10−7 solar masses per year is measured. The main parameters defining the morphology and kinematics of the envelope are evaluated and uncertainties inherent to de-projection are critically discussed. Detailed properties of the equatorial region of the envelope are presented including a measurement of the line width and a precise description of the observed inhomogeneity of both morphology and kinematics. In particular, in addition to the presence of a previously observed spiral enhancement of the morphology at very small Doppler velocities, a similarly significant but uncorrelated circular enhancement of the expansion velocity is revealed, both close to the limit of sensitivity. The results of the analysis place significant constraints on the parameters of models proposing descriptions of the mass-loss mechanism, but cannot choose among them with confidence.

scholarly journals WORKPLANS: Workshop on Planetary Nebula Observations

Galaxies ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 23 ◽  
Author(s):  
Isabel Aleman ◽  
Jeronimo Bernard-Salas ◽  
Joel H. Kastner ◽  
Toshiya Ueta ◽  
Eva Villaver
Keyword(s):  
Observational Data ◽  
Planetary Nebula ◽  
Dust Emission ◽  
Planetary Nebulae ◽  
Research Field ◽  
Theoretical Modeling ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Open Questions ◽  
Giant Branch Stars

This workshop is the second of the WORKPLANS series, which we started in 2016. The main goal of WORKPLANS is to build up a network of planetary nebulae (PNe) experts to address the main open questions in the field of PNe research. The specific aims of the WORKPLANS workshop series are (i) to discuss and prioritize the most important topics to be investigated by the PN community in the following years; (ii) to establish a network of excellent researchers with complementary expertise; (iii) to formulate ambitious observing proposals for the most advanced telescopes and instrumentation presently available (ALMA, SOFIA, VLT, GTC, HST, etc.), addressing those topics; and (iv) to develop strategies for major proposals to future observatories (JWST, ELT, SPICA, Athena, etc.). To achieve these goals, WORKPLANS II brought together experts in all key sub-areas of the PNe research field, namely: analysis and interpretation of PNe observational data; theoretical modeling of gas and dust emission; evolution from Asymptotic Giant Branch stars (PNe progenitors) to PNe; and the instrumentation and technical characteristics of the relevant observatories.

scholarly journals Asymptotic Giant Branch Stars in the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 363-364
Author(s):  
Neill Reid ◽  
J. R. Mould
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Red Giants ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Satellite Systems ◽  
Luminosity Functions ◽  
Theoretical Predictions

Since the pioneering objective prism surveys by Westerlund (1960) and Blanco et al. (1980), the Magellanic Clouds have proved a fruitful site for exploring the evolution of AGB stars. We have used photometric techniques to extend the prism C-star surveys to M- and S-type AGB stars, constructing luminosity functions and obtaining spectra of individual stars for comparison with theoretical predictions. We have concentrated on the Large Magellanic Cloud (LMC), but we have recently obtained observations of luminous red giants in a region of the Small Magellanic Cloud (SMC). In this paper we compare the results from these studies of the two satellite systems.

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