Results 21 to 30 of about 14,221 (195)
Toward Planetesimals: Dense Chondrule Clumps in the Protoplanetary Nebula [PDF]
The Astrophysical Journal, 2008 Astrophys.
Jeffrey N. Cuzzi +2 more
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Small Protoplanetary Disks in the Orion Nebula Cluster and OMC1 with ALMA [PDF]
The Astrophysical Journal, 2021 Abstract The Orion Nebula Cluster (ONC) is the nearest dense star-forming region at ∼400 pc away, making it an ideal target to study the impact of high stellar density and proximity to massive stars (the Trapezium) on protoplanetary disk evolution.
Otter, Justin A. +7 more
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Neutral carbon in the protoplanetary nebulae CRL 618 and CRL 2688 [PDF]
The Astrophysical Journal, 1997 The 609u 3P1 -> 3P0 line of neutral atomic carbon has been detected in the protoplanetary nebulae CRL 618 and CRL 2688. CI appears to be about 7% as abundant as CO in CRL 2688, and 70% as abundant as CO in CRL 618. CI emission arises primarily from the slow component of the wind from these objects.
arxiv +6 more sources
How unique is the protoplanetary nebula star HR 4049? [PDF]
Symposium - International Astronomical Union, 1987 The late B-supergiant HR 4049 is peculiar in different respects: (1) It is located far from the galactic plane (b = 23°); (2) It is a variable with a large amplitude and on a long time scale (Waelkens and Rufener, 1983); (3) It has a spectacular infrared excess (Lamers et al., 1986).
C. L. Waelkens, L. B. F. M. Waters
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A SUBMILLIMETER ARRAY SURVEY OF PROTOPLANETARY DISKS IN THE ORION NEBULA CLUSTER [PDF]
The Astrophysical Journal, 2010 Accepted for publication in ApJ, 36 pages, 10 ...
Rita K. Mann, Jonathan P. Williams
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The Planetary Science Journal, 2023 Converging lines of evidence show that protoplanetary disks are complex environments hosting spatial and temporal variability at multiple scales.
Roger R. Fu +5 more
doaj +1 more source
Chemistry in Protoplanetary Nebulae [PDF]
Symposium - International Astronomical Union, 1992 We have investigated gas-phase chemistry in a remnant red giant wind, during transition to a planetary nebula, using the interacting stellar winds model. Rapid destruction by UV of most existing molecules is predicted, within ~ 100 yrs of the core star heating up, suggesting that the large molecules in CRL 618 may be destroyed within decades.
Tom J. Millar +2 more
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Chemistry in a protoplanetary nebula [PDF]
Monthly Notices of the Royal Astronomical Society, 1992 The gas-phase chemistry in the remnant superwind of a carbon-rich red giant star, during its transition to a planetary nebula, is investigated. The interacting stellar winds model is used. It is found that during the first few hundred years of transition, significant abundances of a few small molecules and ions (e.g. CH + , CH + 2 , CH + 3 , CH, CH 2
Howe, D.A., Millar, TJ, Williams, D.A.
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The Astrophysical Journal, 2023 Using self-consistent models of turbulent particle growth in an evolving protoplanetary nebula of solar composition, we find that recently proposed local metallicity and Stokes number criteria necessary for the streaming instability to generate ...
Paul R. Estrada, Orkan M. Umurhan
doaj +1 more source
The chemistry of protoplanetary nebulae [PDF]
Astronomy & Astrophysics, 2003 We describe the chemistry occurring in a dense slab of outwardly expanding gas in the post-AGB phase of stellar evolution. Despite the high flux of UV photons from the central star, the intrinsic dust extinction in the slab prevents rapid photodissociation and allows chemical reactions to make a variety of gas-phase species, some complex.
Albert A. Zijlstra +4 more
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