Results 21 to 30 of about 536 (176)
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
openalex +5 more sources
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
openaire +2 more sources
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 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.
openaire +2 more sources
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
openaire +2 more sources
Study of protoplanetary nebulae [PDF]
Proceedings of the International Astronomical Union, 2016 AbstractWe have performed 3D hydrodynamic simulations of a symmetrical jet ejection following previous works (Raga et al. 2009, Riera et al. 2014, Velázquez et al. 2014). The jet is emitted from a binary system in elliptical orbit, and its direction changes describing a precession cone.
D. Estrella +4 more
openaire +1 more source
Fast outflows in protoplanetary nebulae and young planetary nebulae observed by Herschel/HIFI [PDF]
Astronomy & Astrophysics, 2021 Context. Fast outflows and their interaction with slow shells (generally known as the fossil circumstellar envelope of asymptotic giant branch stars) play an important role in the structure and kinematics of protoplanetary and planetary nebulae (pPNe, PNe).
Lorenzo, M. +6 more
openaire +5 more sources
Vertical distribution and kinematics of protoplanetary nebulae in the galaxy [PDF]
Astronomy Letters, 2017 18 pages, 4 figures, 2 ...
Anisa T. Bajkova, Vadim V. Bobylev
openaire +3 more sources
Evolution of protoplanetary nebulae
The Astrophysical Journal, 1989 Model spectra of protoplanetary nebulae have been calculated assuming that mass loss on the asymptotic giant branch terminates when the hydrogen envelope is almost totally depleted. The models predict spectral characteristics of protoplanetary nebulae which can be used to search for new candidates of protoplanetary nebulae in the IRAS Low Resolution ...
Kevin Volk, Sun Kwok
openaire +2 more sources