Results 11 to 20 of about 995 (179)
Astronomy & AstrophysicsContext. The high frequency resolution of the four-year time series collected by the space-borne telescope Kepler provides us the opportunity to study the seismic mode structure of highly luminous giants in great detail.
Dréau G. +3 more
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The Asymptotic Giant Branch [PDF]
Symposium - International Astronomical Union, 1997 For stars with masses between about 1 and 8 M⊙ the ascent of the Asymptotic Giant Branch (AGB) is the last nuclear powered evolutionary stage. Following this the stars eject a planetary nebula and fade as white dwarfs. Although only short in duration, the AGB is very important due to the nucleosynthesis which occurs.
J. C. Lattanzio, C. A. Frost
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On the Termination of Asymptotic Giant Branch Evolution [PDF]
Symposium - International Astronomical Union, 1984 The evolution of planetary nebula (PN) nuclei has been studied at masses of 0.60, 0.70 and 0.76 M⊙, and for the ejection of the PN at various phases of a helium shell flash cycle. The evolution at high luminosities takes longer for nuclei resulting from PN ejection at shell flash peak than it does for those resulting from ejection in the inter-flash ...
P. R. Wood, D. J. Faulkner
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Asymptotic Giant Branch predictions: Theoretical uncertainties [PDF]
Astronomy & Astrophysics, 2001 In this paper we investigate the level of agreement between observations and "new" Asymptotic Giant Branch (AGB) models, as produced by updating the physical inputs adopted in previous stellar computations. One finds that the new physics increases the predicted luminosity of Horizontal Branch (HB) and AGB stellar structures by a similar amount, keeping
Cassisi S +4 more
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Luminosity Functions for Asymptotic Giant Branch Stars [PDF]
Symposium - International Astronomical Union, 1984 To understand the evolution of carbon and oxygen rich asymptotic giant branch (AGB) stars it is important to observationally establish the relations between parameters such as luminosity, age, and metallicity. The existence of luminous (brighter than the top of the first giant branch) AGB stars in clusters in the Magellanic Clouds (Mould and Aaronson ...
Jay A. Frogel, V.M. Blanco
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Vortices in the Wakes of Asymptotic Giant Branch Stars [PDF]
The Astrophysical Journal, 2007 Vortices have been postulated at a range of size scales in the universe, including at the stellar-size scale. While hydrodynamically simulating the wind from an asymptotic giant branch (AGB) star moving through and sweeping up its surrounding interstellar medium (ISM), we have found vortices on the size scale of 10-1 to 101 pc in the wake of the star ...
Wareing, C. J. +2 more
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Turbulent dynamo in asymptotic giant branch stars [PDF]
Monthly Notices of the Royal Astronomical Society, 2002 Using recent results on the operation of turbulent dynamos, we show that a turbulent dynamo can amplify a large scale magnetic field in the envelopes of asymptotic giant branch (AGB) stars. We propose that a slow rotation of the AGB envelope can fix the symmetry axis, leading to the formation of an axisymmetric magnetic field structure.
Soker, Noam, Zoabi, Essam
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Mass loss on the Asymptotic Giant Branch [PDF]
Proceedings of the International Astronomical Union, 2006 Mass loss on the Asymptotic Giant Branch provides the origin of planetary nebulae. This paper reviews several relevant aspects of AGB evolution: pulsation properties, mass loss formalisms and time variable mass loss, evidence for asymmetries on the AGB, binarity, ISM interaction, and mass loss at low metallicity.
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The Galactic distribution of asymptotic giant branch stars [PDF]
Monthly Notices of the Royal Astronomical Society, 2002 We study the Galactic distribution of ~10,000 Asymptotic Giant Branch (AGB) stars selected by IRAS colors and variability index. The distance to each star is estimated by assuming a narrow luminosity function and a model-derived bolometric correction.
Jackson, T., Ivezic, Z., Knapp, G. R.
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Optical Spectropolarimetry of Asymptotic Giant Branch and Post–Asymptotic Giant Branch Stars
The Astrophysical Journal, 2006 Spectropolarimetric observations are presented for 21 AGB stars, 13 proto-planetary nebulae (PPNs), and two R CrB-type stars. The spectra cover the wavelength range from ~4200 to 8400 A with 16 A resolution. Among the AGB stars, 8 of 14 M giants, five of six carbon stars, and zero of one S star showed intrinsic polarization.
John H. Bieging +3 more
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