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Related papers: The nebula around the binary post-AGB star 89 Herc…

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Cometary globule 12 is a relatively little investigated medium- and low mass star forming region 210 pc above the Galactic plane. NIR J, H, and Ks imaging and stellar photometry is used to analyse the stellar content and the structure of CG…

Astrophysics of Galaxies · Physics 2015-05-14 Lauri K. Haikala , Bo Reipurth

We have carried out high-resolution spectroscopic observations of the carbon star V Hya, covering the 4.6 micron band of CO. These data, taken over 7 epochs, show that the circumstellar environment of V Hya consists of a complex…

Astrophysics of Galaxies · Physics 2011-02-11 Raghvendra Sahai , Ben E. K. Sugerman , Kenneth Hinkle

The goal is to build up a simple dynamical model for the out-flowing circumstellar envelope around AGB stars in a wide binary system to explore the parameter dependence of the geometrical characteristics of column density patterns. An AGB…

Astrophysics · Physics 2009-11-13 J. H. He

The proto-planetary Red Rectangle nebula is powered by HD 44179, a spectroscopic binary (P = 318 d), in which a luminous post-AGB component is the primary source of both luminosity and current mass loss. Here, we present the results of a…

We present high resolution millimeter continuum and CO line observations for the circumbinary disk around V892 Tau to constrain the stellar and disk properties. The total mass of the two near-equal-mass A stars is estimated to be…

We study the chemical abundances of a wide sample of 142 Galactic planetary nebulae (PNe) with good quality observations, for which the abundances have been derived more or less homogeneously, thus allowing a reasonable comparison with…

Solar and Stellar Astrophysics · Physics 2017-09-06 P. Ventura , L. Stanghellini , F. Dell'Agli , D. A. Garcia-Hernandez

The S-type asymptotic giant branch (AGB) star $\pi^{1}$ Gruis has a known companion at a separation of $\approx$400 AU. The envelope structure, including an equatorial torus and a fast bipolar outflow, is rarely seen in the AGB phase and is…

Solar and Stellar Astrophysics · Physics 2017-09-28 L. Doan , S. Ramstedt , W. H. T. Vlemmings , S. Höfner , E. De Beck , F. Kerschbaum , M. Lindqvist , M. Maercker , S. Mohamed , C. Paladini , M. Wittkowski

We analyse continuum and molecular emission, observed with ALMA, from the dust-enshrouded intermediate-mass AGB star OH 30.1 -0.7. We find a secondary peak in the continuum maps, "feature B", separated by 4.6" from the AGB star, which…

Adaptive optics observations in the infrared (VLT/NACO, Kervella et al. 2014) and visible (VLT/SPHERE, Kervella et al. 2015) domains revealed that the nearby AGB star L2 Pup (d=64 pc) is surrounded by a dust disk seen almost edge-on.…

Solar and Stellar Astrophysics · Physics 2015-12-14 P. Kervella , M. Montargès , E. Lagadec

The mechanisms responsible for chemical depletion across diverse astrophysical environments are not yet fully understood. In this paper, we investigate chemical depletion in post-AGB/post-RGB binary stars hosting second-generation…

Solar and Stellar Astrophysics · Physics 2025-03-03 Maksym Mohorian , Devika Kamath , Meghna Menon , Anish M. Amarsi , Hans Van Winckel , Claudia Fava , Kateryna Andrych

The origin of chemically peculiar stars and non-zero eccentricity in evolved close binaries have been long-standing problems in binary stellar evolution. Answers to these questions may trace back to an intense mass transfer during AGB…

Solar and Stellar Astrophysics · Physics 2020-04-15 Zhuo Chen , Natalia Ivanova , Jonathan Carroll-Nellenback

Context. The Mass loss of Evolved StarS (MESS) sample observed with PACS on board the Herschel Space Observatory revealed that several asymptotic giant branch (AGB) stars are surrounded by an asymmetric circumstellar envelope (CSE) whose…

Stars with initial masses between $\sim0.8$ and 8~$M_\odot$ present copious mass loss during the asymptotic giant branch (AGB) at the end of their lives. The accepted mass-loss mechanism requires radiation pressure acting on dust grains…

Solar and Stellar Astrophysics · Physics 2020-03-16 T. Khouri , W. H. T. Vlemmings , C. Paladini , C. Ginski , E. Lagadec , M. Maercker , P. Kervella , E. De Beck , L. Decin , A. de Koter , L. B. F. M. Waters

We have derived elemental abundances for a sample of nine IRAS sources with colours similar to those of post-AGB stars. For IRAS 01259+6823, IRAS 05208-2035, IRAS 04535+3747 and IRAS 08187-1905 this is the first detailed abundance analysis…

Solar and Stellar Astrophysics · Physics 2011-09-09 S. Sumangala Rao , Sunetra Giridhar , David L. Lambert

We review the observed properties of extremely hot hydrogen-deficient post-AGB stars of spectral type [WC] and PG1159. Their H-deficiency is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse, laying bare…

Astrophysics · Physics 2009-11-13 K. Werner , F. Herwig

We aim to study the dust distribution in the central regions of the Keplerian disk of the Red Rectangle, the prototype of binary post-AGB stars with rotating circumbinary disks, and to compare it with the distribution of relevant molecular…

Solar and Stellar Astrophysics · Physics 2023-09-15 V. Bujarrabal , J. Alcolea , A. Castro-Carrizo , J. Kluska , C. Sanchez Contreras , H. Van Winckel

We study the nature of Gomez's Hamburger (IRAS 18059-3211), a nebula that has been proposed to be a post-AGB object. Such a classification is not confirmed; instead, we argue that it will be a key object in the study of disks rotating…

Astrophysics · Physics 2009-06-23 V. Bujarrabal , K. Young , D. Fong

Stellar light from an AGB star is scattered by the circumstellar dust and polarized in the direction perpendicular to the source. Therefore, images of circumstellar envelopes around AGB stars in polarized light traces the dust distribution…

Solar and Stellar Astrophysics · Physics 2010-11-10 S. Ramstedt , M. Maercker , G. Olofsson , H. Olofsson , F. L. Schöier

Observational evidence for strong magnetic fields throughout the envelopes of evolved stars is increasing. Many of the instruments coming on line in the near-future will be able to make further contributions to this field. Specifically,…

Solar and Stellar Astrophysics · Physics 2010-10-07 Wouter Vlemmings

Classical barium stars are binary systems which consist of a late-type giant enriched in carbon and slow neutron capture (s-process) elements and an evolved white dwarf (WD) that is invisible at optical wavelengths. The youngest observed…

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