scholarly journals The Macquarie–Strasbourg Connection

2010 ◽  
Vol 27 (2) ◽  
pp. 128-128
Author(s):  
Agnès Acker
Keyword(s):  
High Resolution ◽  
Stellar Evolution ◽  
Representative Sample ◽  
Galactic Plane ◽  
Planetary Nebulae ◽  
Galactic Evolution ◽  
Galactic Bulge ◽  
Late Stages ◽  
Remarkable Advance

Planetary nebulae (PN) are powerful tracers of both stellar and Galactic evolution. The capacity of PN to perform these studies is critically dependent on the size of the population, a major problem with a remarkable advance thanks to Quentin Parker and his team, who from 1997 to 2008 discovered an unprecedented sample of ∼1250 PN with the deep, high resolution AAO/UKST SuperCosmos Halpha Survey (SHS) of the Southern Galactic Plane (Parker et al. 2005), doubling the sample collected over the previous century, and leading to ∼2700 for the number of known PN today. A highly productive collaboration between Quentin and I has been established since 2001. Our complementary levels of expertise and facilities constitute the Macquarie/AAO/Strasbourg H-α Planetary Nebulae Project.The new MASH PN were added to the Centre de Données de Strasbourg as a new PN database continuously updated, and detailed in Parker et al. (2006) and Miszalski et al. (2008). In the framework of a cotutelle agreement between the Strasbourg and Macquarie universities, two PhD projects based on MASH PN have been conducted under the supervision of Quentin and myself, both projects focusing on the mysterious crowded region of the Galactic Bulge. Alan Peyaud proposed new constraints on late stages of stellar evolution and on the dynamics of the Galactic Bulge (defence 21 December 2005, Strasbourg). Brent Miszalski discovered ∼360 new PN (MASH-II) completing the largest and most representative sample of PN towards the Galactic bulge (defence 15 August 2009).

Large planetary nebulae and their significance to the late stages of stellar evolution

1990 ◽  
Vol 359 ◽  
pp. 392 ◽  
Author(s):  
James B. Kaler ◽  
Richard A. Shaw ◽  
Karen B. Kwitter
Keyword(s):  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Late Stages

scholarly journals Kinematic and chemical analysis of PNe in NGC 3109

2016 ◽  
Vol 12 (S323) ◽  
pp. 390-391
Author(s):  
Sheila N. Flores-Dúran ◽  
Miriam Peña ◽  
María T. Ruiz
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Chemical Analysis ◽  
Stellar Evolution ◽  
Planetary Nebulae ◽  
High Resolution Spectroscopy ◽  
Irregular Galaxy ◽  
The One

AbstractWe present high resolution spectroscopy obtained with MIKE-Magellan and MES OAN-SPM of a number of planetary nebulae (PNe) and H ii regions, distributed along the dwarf irregular galaxy NGC 3109 and compare their kinematical behavior with the one of H i data. We aim to determine if there is a kinematical connection among these objects. We also perform a revision of the chemical composition of PNe and H ii regions in this galaxy and discuss it in comparison with stellar evolution models.

scholarly journals Molecular Evolution from AGB Stars to Planetary Nebulae

2011 ◽  
Vol 7 (S280) ◽  
pp. 203-215 ◽  
Author(s):  
Sun Kwok
Keyword(s):  
Chemical Synthesis ◽  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Active Phase ◽  
Molecular Ions ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
The Galaxy ◽  
Short Time ◽  
Late Stages

AbstractThe late stages of stellar evolution from the Asymptotic Giant Branch (AGB) to planetary nebulae represent the most active phase of molecular synthesis in a star's life. Over 60 molecular species, including inorganics, organics, radicals, chains, rings, and molecular ions have been detected in the circumstellar envelopes of evolved stars. Most interestingly, complex organic compounds of aromatic and aliphatic structures are synthesized over very short time intervals after the end of the AGB. Also appeared during the post-AGB evolution are the unidentified 21 and 30 μm emission features, which are believed to originate from carbonaceous compounds.The circumstellar environment is an ideal laboratory for the testing of theories of chemical synthesis. The distinct spectral behavior among AGB stars, proto-planetary nebulae (PPN), and planetary nebulae (PN) and the short evolutionary time scales that separate these stages pose severe constraints on models. In this paper, we will present an observational summary of the chemical synthesis in the late stages of stellar evolution, discuss chemical and physical processes at work, and speculate on the possible effects these chemical products have on the Galaxy and the Solar System.

High-resolution imaging and the H-R diagram of Galactic bulge planetary nebulae

1990 ◽  
Vol 365 ◽  
pp. 640 ◽  
Author(s):  
M. A. Dopita ◽  
J. P. Henry ◽  
I. R. Tuohy ◽  
B. L. Webster ◽  
E. H. Roberts ◽  
...  
Keyword(s):  
High Resolution ◽  
Planetary Nebulae ◽  
High Resolution Imaging ◽  
Galactic Bulge ◽  
Resolution Imaging

Newly discovered Planetary Nebulae population in Andromeda (M31): PN Luminosity function and implications for the late stages of stellar evolution

2018 ◽  
Vol 14 (S343) ◽  
pp. 201-205
Author(s):  
Souradeep Bhattacharya ◽  
Magda Arnaboldi ◽  
Johanna Hartke ◽  
Ortwin Gerhard ◽  
Valentin Comte ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Luminosity Function ◽  
Stellar Population ◽  
Narrow Band ◽  
Broad Band ◽  
Planetary Nebulae ◽  
Magellanic Clouds ◽  
Outer Disk ◽  
Late Stages ◽  
Uniform Area

AbstractStars with masses between ∼0.7 and 8 M⊙ end their lives as Planetary Nebulae (PNe). With the MegaCam at CFHT, we have carried out a survey of the central 16 sq. degrees of Andromeda (M31) reaching the outer disk and halo, using a narrow-band [OIII]5007 and a broad-band g filter. This survey extends previous PN samples both in uniform area coverage and depth. We identify ∼4000 PNe in M31, of which ∼3000 are new discoveries. We detect PNe down to ∼6 mag below the bright cut-off of the PN luminosity function (PNLF), ∼2 mag deeper than in previous works. We detect a steep rise in the number of PNe at ∼4.5 mag fainter than the bright cut-off. It persists as we go radially outwards and is steeper than that seen in the Magellanic clouds. We explore possible reasons for this rise, which give insights into the stellar population of M31.

scholarly journals The IAC morphological catalog of Northern Galactic Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 24-25 ◽  
Author(s):  
A. Manchado ◽  
M. A. Guerrero ◽  
L. Stanghellini ◽  
M. Serra-Ricart
Keyword(s):  
Magnetic Fields ◽  
Mass Loss ◽  
Stellar Evolution ◽  
Morphological Study ◽  
Planetary Nebulae ◽  
Asymptotic Giant Branch ◽  
Intermediate Mass ◽  
Evolutionary Scheme ◽  
Late Stages

Planetary Nebulae (PNs) are highly representative of the late stages of intermediate mass stellar evolution. However, there are still many unresolved questions in their evolutionary scheme. Mass loss processes during the Asymptotic Giant Branch (AGB) are not fully understood. Binarity, rotation and magnetic fields may play an important role in PNs formation. The morphological study of PNs will help us to address those questions, and therefore a meaningful homogeneous database is needed.

scholarly journals Stellar Evolution from AGB to Planetary Nebulae

2008 ◽  
Vol 4 (S252) ◽  
pp. 197-203 ◽  
Author(s):  
Sun Kwok
Keyword(s):  
Magnetic Field ◽  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Central Star ◽  
Dynamical Models ◽  
One Dimensional ◽  
Physical Mechanisms ◽  
Fast Wind ◽  
Symmetric Structures ◽  
Late Stages

AbstractPlanetary nebulae are formed by an interacting winds process where the remnant of the AGB wind is compressed and accelerated by a later-developed fast wind from the central star. One-dimensional dynamical models have successfully explained the multi-shell (bubble, shell, crown, haloes) structures and the kinematics of planetary nebulae. However, the origin of the diverse asymmetric morphology of planetary nebulae is still not understood. Recent observations in the visible, infrared, and the submillimeter have suggested that the AGB mass loss becomes aspherical in the very late stages, forming an expanding torus around the star. A fast, highly collimated wind then emerges in the polar directions and carves out a cavity in the AGB envelope to form a bipolar nebula. Newly discovered structures such as concentric arcs, 2-D rings, multiple lobes, and point-symmetric structures suggest that both the slow and fast winds may have temporal and directional variations, and precession can play a role in the shaping of planetary nebulae. In this paper, we review the latest observations of planetary nebulae and proto-planetary nebulae and discuss the various physical mechanisms (rotation, binary, magnetic field, etc) that could lead to the observed morphologies.

scholarly journals A study of AGB stars in LMC clusters

2008 ◽  
Vol 4 (S256) ◽  
pp. 397-402
Author(s):  
Thomas Lebzelter ◽  
Michael T. Lederer ◽  
Sergio Cristallo ◽  
Oscar Straniero ◽  
Kenneth H. Hinkle
Keyword(s):  
High Resolution ◽  
Stellar Evolution ◽  
Near Infrared ◽  
Mass Range ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Near Infrared Spectra ◽  
Model Predictions ◽  
First Time ◽  
Late Stages

AbstractLMC clusters offer an outstanding opportunity to investigate the late stages of stellar evolution of stars in the mass range between 1.5 and 2 M⊙. In this presentation we will focus on our results on mixing events during the evolution along the Asymptotic Giant Branch (AGB). Surface abundances have been determined for a number of cluster AGB stars from high resolution near infrared spectra. We show for the first time the evolution of C/O and 12C/13C ratios along a cluster AGB. The change of both quantities due to dredge up events is compared with model predictions. Our results indicate the late occurrence of a moderate extra-mixing in some cases.

scholarly journals Spectra of the Central Stars of Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 339-354 ◽  
Author(s):  
Lawrence H. Aller
Keyword(s):  
Observational Data ◽  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Spectral Energy ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
Spectroscopic Observations ◽  
Theoretical Investigations ◽  
Late Stages ◽  
Central Stars

The central stars of planetary nebulae represent seemingly well-defined late stages of stellar evolution. Theoretical investigations with predictions of evolutionary tracks impose difficult requirements for observational data. Measurements of spectral energy distributions, of colors, and of magnitudes, and spectroscopic observations are all urgently needed.

scholarly journals On the Mass and Luminosity of V348 Sgr

1985 ◽  
Vol 87 ◽  
pp. 221-223
Author(s):  
D. Schönberner
Keyword(s):  
Stellar Evolution ◽  
Short Note ◽  
Planetary Nebulae ◽  
Rosetta Stone ◽  
Unique Object ◽  
Helium Star ◽  
Late Stages

In this short note, an attempt has been made to estimate mass and luminosity of the unique object, V348 Sgr, which appears to be a “Rosetta Stone” for our understanding of late stages of stellar evolution, as i)its photosphere is virtually hydrogen-free and carbon-rich as with an extreme helium star,ii)it fades irregularly as does a R CrB-star andiii)it is surrounded by a nebular shell similar to that surrounding Planetary Nebulae.We know a great deal more about the above-mentioned objects than about V348 Sgr and this knowledge can be used to obtain estimates on mass and luminosity of the latter.

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