Results 151 to 160 of about 4,442 (177)

Hot Post-AGB Stars

2001
From the study of IRAS sources with far-IR colors similar to planetary nebulae (PNe), several proto-planetary nebulae with hot (OB) post-AGB central stars have been detected. These stars form an evolutionary link between the cooler G,F,A supergiant stars that have evolved off the Asymptotic Giant Branch (AGB) and the hot (OB) central stars of PNe.
M. Parthasarathy, G. Gauba, T. Fujii, Y. Nakada   +3 more
openaire   +1 more source

Circumstellar Arcs in AGB Post-AGB Stars

2001
One of the most unexpected discoveries of the Hubble Space Telescope (HST) observations of planetary nebulae (PN) is the revelation of concentric arcs in the nebulae. As of 2000, circumstellar arcs have been found in three PN (NGC 7027, Bond 2000; NGC 6543, Bond 2000, Terzian & Hajian 2000; Hb 5, Balick & Wilson 2000), and three proto-planetary nebulae
Sun Kwok, Kate Y. L. Su, J. A. Stoesz
openaire   +1 more source

AGB and POST-AGB STARS: an Overview

1997
In the last phase of their existence stars of low and intermediate main-sequence mass, M ms below about 6 M ⊘, become very luminous red giants; in the HR-diagram they populate the “Asymptotic Giant Branch”. “AGB” stars are very rare: this phase is very brief and lasts perhaps 105 yr.
openaire   +1 more source

Chemical Compositions of Post-AGB Stars

Symposium - International Astronomical Union, 1991
Objects that may be in a post-AGB evolutionary stage include high-latitude supergiants, UU Her and RV Tau variables, and IRAS sources identified with A- to G-type supergiants. Photospheric abundance analyses of such objects typically reveal moderate to extreme iron-group deficiencies, consistent with membership in the thick-disk or halo populations ...
openaire   +1 more source

The Circumstellar Envelope of The Post-AGB Star

2000
OH17.7-2.0 is a typical POST-AGB star. We have observed the circumstellar OH maser radiation of OH17.7-2.0 using Parkes 64m radiotelescope, Australia. We have obtained four peaks in its spectra: the both peaks are from weaker-sources found in our observation run, and the other two are from the stronger-source observed previously.
Yu Zhi-yao, J. Chapman
openaire   +1 more source

Spectroscopical Masses of Post-AGB Stars

2001
The literature has been reviewed in search of available spectroscopic parameters for the post-AGB objects. The surface gravity and the effective temperature have been used for determination of spectroscopic masses from comparison with theoretical evolutionary tracks. The derived distribution of masses is relatively narrow and concentrates around 0.55 M⊙
openaire   +1 more source

Jet parameters for a diverse sample of jet-launching post-AGB binaries

Monthly Notices of the Royal Astronomical Society, 2021
Dylan Bollen, D Kamath, H Van Winckel
exaly  

A census of post-AGB stars in Gaia DR3: evidence for a substantial population of Galactic post-RGB stars

Monthly Notices of the Royal Astronomical Society: Letters, 2022
R D Oudmaijer, M Vioque
exaly  

Spitzer Space Telescope spectra of post-AGB stars in the Large Magellanic Cloud – polycyclic aromatic hydrocarbons at low metallicities

Monthly Notices of the Royal Astronomical Society, 2014
M Matsuura, T Lloyd Evans, Bruce J Hrivnák   +2 more
exaly  

Extrinsically metal-poor stars: photospheric chemical depletion in post-AGB/post-RGB stars in the Large Magellanic Cloud

Monthly Notices of the Royal Astronomical Society, 2019
D Kamath, H Van Winckel, Kamath Devika   +2 more
exaly