Results 11 to 20 of about 42,848 (232)
The Astronomical JournalProtoplanetary nebulae (PPNs) represent a critical evolutionary bridging stage between the asymptotic giant branch (AGB) and planetary nebula (PN) stages. Their dynamical structures provide key insights into late stellar evolution. Here, we report CO and
Hao-Min Sun, Yong Zhang, Sheng-Li Qin
doaj +3 more sources
AN ASYMMETRIC JET-LAUNCHING MODEL FOR THE PROTOPLANETARY NEBULA CRL 618 [PDF]
The Astrophysical Journal, 2014 We propose an asymmetrical jet ejection mechanism in order to model the mirror symmetry observed in the lobe distribution of some protoplanetary nebulae (pPNe), such as the pPN CRL 618. 3D hydrodynamical simulations of a precessing jet launched from an orbiting source were carried out including an alternation in the ejections of the two outflow lobes ...
P. F. Velázquez +3 more
semanticscholar +6 more sources
Condensation Front Migration in a Protoplanetary Nebula [PDF]
The Astrophysical Journal, 2005 Condensation front dynamics are investigated in the mid-solar nebula region. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary condensation fronts for selected species. These fronts are found to migrate inwards from the far-nebula to final positions during a period of 10(exp 7 ...
Sanford S. Davis
semanticscholar +4 more sources
UV Monochromatic Imaging of the Protoplanetary Nebula Hen 3-1475 Using HST STIS
Galaxies, 2018 Collimated outflows and jets play a critical role in shaping planetary nebulae (PNe), especially in the brief transition from a spherical AGB envelope to an aspherical PN, which is called the protoplanetary nebula (pPN) phase.
Xuan Fang +5 more
doaj +2 more sources
Small Protoplanetary Disks in the Orion Nebula Cluster and OMC1 with ALMA [PDF]
Astrophysical Journal, 2021 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.
Justin A. Otter +7 more
semanticscholar +5 more sources
Protoplanetary Disks in the Orion Nebula Cluster: Gas-disk Morphologies and Kinematics as Seen with ALMA [PDF]
Astrophysical Journal, 2020 We present Atacama Large Millimeter Array CO(3 − 2) and HCO+(4 − 3) observations covering the central 1.′5 × 1.′5 region of the Orion Nebula Cluster (ONC).
Ryan D. Boyden, Josh A. Eisner
semanticscholar +4 more sources
Evidence for Magnetically‐Driven Accretion in the Distal Solar System
AGU AdvancesPaleomagnetic measurements of meteorites indicate that magnetic fields existed in the inner solar nebula capable of driving accretion at rates similar to those observed for young stellar objects with protoplanetary disks.
Elias N. Mansbach +11 more
doaj +2 more sources
The Astrophysical JournalMolecular observations were conducted of the protoplanetary nebula (PPN) Frosty Leo (IRAS 09371+1212) using the 12 m antenna and the Submillimeter Telescope of the Arizona Radio Observatory at 1–3 mm. In addition to CO, multiple transitions were detected
K. R. Gold, L. M. Ziurys
doaj +2 more sources
Toward Planetesimals: Dense Chondrule Clumps in the Protoplanetary Nebula [PDF]
The Astrophysical Journal, 2008 Astrophys.
Cuzzi, Jeffrey N. +2 more
openaire +4 more sources
CHEMICAL EVOLUTION OF TURBULENT PROTOPLANETARY DISKS AND THE SOLAR NEBULA [PDF]
The Astrophysical Journal Supplement Series, 2011 This is the second paper in a series where we study the influence of transport processes on the chemical evolution of protoplanetary disks. Our analysis is based on a flared alpha-model of the DM Tau system, coupled to a large gas-grain chemical network.
D. Semenov, D. S. Wiebe
openalex +3 more sources