Results 21 to 30 of about 301,064 (245)
Circumstellar Molecular Envelopes [PDF]
Symposium - International Astronomical Union, 1997 The results of C17O and C18O observations of low luminosity young stars are discussed and the derived properties of the circumstellar molecular envelopes described. Much of the circumstellar material is quiescent and cold. The youngest sources have envelopes which contain up to ∼ 0.3 M⊙ of material within 3000–4000 AU of the central star. From a survey
G. A. Fuller, E. F. Ladd
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The Role of Internal Photons on the Chemistry of the Circumstellar Envelopes of AGB Stars [PDF]
Astrophysical Journal, 2019 Recent high spatial resolution observations of gas and dust in the circumstellar envelopes (CSEs) of AGB stars indicate morphologies much more complex than the smooth density distributions generated by spherically symmetric, constant mass-loss rates.
M. Van de Sande, T. Millar
semanticscholar +1 more source
AGB Stars and Their Circumstellar Envelopes. I. the VULCAN Code
Universe, 2021 The interplay between AGB interiors and their outermost layers, where molecules and dust form, is a problem of high complexity. As a consequence, physical processes like mass loss, which depend on the chemistry of the circumstellar envelope, are often ...
Sergio Cristallo +4 more
doaj +1 more source
Phosphorus in circumstellar envelopes [PDF]
Monthly Notices of the Royal Astronomical Society, 2001 ABSTRA C T We have investigated the chemistry of phosphorus-bearing compounds in the circumstellar envelopes of both oxygen-rich and carbon-rich evolved stars. In accordance with thermodynamic calculations of photospheric chemistry, we have assumed that the dominant forms of phosphorus in the inner circumstellar envelope (CSE) are PS and HCP in each ...
D. D. S. MacKay, S. B. Charnley
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Crescent-shaped Molecular Outflow from the Intermediate-mass Protostar DK Cha Revealed by ALMA
The Astrophysical Journal, 2023 We report on an Atacama Large Millimeter/submillimeter Array study of the Class I or II intermediate-mass protostar DK Cha in the Chamaeleon II region.
Naoto Harada +8 more
doaj +1 more source
The Chemistry of Cool Circumstellar Envelopes [PDF]
Symposium - International Astronomical Union, 1987 We have developed a time-dependent chemical kinetic model to describe the chemistry in the circumstellar envelopes of cool stars, with particular reference to IRC + 10216. Our detailed calculations show that ion-molecule reactions are important in the formation of many of the species observed in IRC + 10216.
L.A.M. Nejad, T. J. Millar
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Search for Hydrogenated C60 (Fulleranes) in Circumstellar Envelopes [PDF]
, 2017 The recent detection of fullerene (C60) in space and the positive assignment of five diffuse interstellar bands to reinforce the notion that fullerene-related compounds can be efficiently formed in circumstellar envelopes and be present in significant ...
Y. Zhang 张 +3 more
semanticscholar +1 more source
The photodissociation of CO in circumstellar envelopes
Astrophysical Journal, 1988 G. Mamon, A. Glassgold, P. Huggins
semanticscholar +3 more sources
ChemPhysChem, Volume 24, Issue 22, November 16, 2023., 2023 Can the radical C5N bind a free electron to form a dipole‐bound state? The answer is sought using multi‐reference ab initio quantum chemical methods. Abstract We present results of quantum structure calculations aimed at demonstrating the possible existence of dipole‐bound states (DBS) for the anion C5N- ${{\rm{C}}_5 {\rm{N}}^ - }$ , a species already ...
Stanka Jerosimić +4 more
wiley +1 more source
Open clusters: III. Fundamental parameters of B stars in NGC 6087, NGC 6250, NGC 6383 and NGC 6530. B type stars with circumstellar envelopes [PDF]
, 2017 Context. Stellar physical properties of star clusters are poorly known. Aims. Our goals are to perform a spectrophotometric study of the B star population in open clusters to derive accurate stellar parameters, search for the presence of circumstellar ...
Y. Aidelman +7 more
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