Results 271 to 280 of about 191,657 (282)
Some of the next articles are maybe not open access.
Astrophysics and Space Science, 1996
This review summarizes spectroscopic and imaging results obtained on board the Infrared Space Observatory (ISO) on well-known planetary nebulae: the young nebula NGC 7027, and two fully evolved nearby nebulae, the Dumbbell and the Helix.
openaire +2 more sources
This review summarizes spectroscopic and imaging results obtained on board the Infrared Space Observatory (ISO) on well-known planetary nebulae: the young nebula NGC 7027, and two fully evolved nearby nebulae, the Dumbbell and the Helix.
openaire +2 more sources
Molecules and solids in planetary nebulae and proto-planetary nebulae
Advances in Space Research, 2007Abstract Recent millimeter-wave and infrared spectroscopic observations have identified a large number of organic molecules through their rotational and vibrational transitions. In particular, the detections of the stretching and bending modes of aliphatic and aromatic compounds have revealed a continuous synthesis of organic materials at the late ...
openaire +4 more sources
Astrophysics of Gaseous Nebulae and Active Galactic Nuclei
, 1989Preface Preface to First Edition General Introduction Photoionization Equilibrium Thermal Equilibrium Calculation of Emitted Spectrum Comparison of Theory with Observations Internal Dynamics of Gaseous Nebulae Interstellar Dust Infrared Radiation and ...
D. Osterbrock, G. Ferland
semanticscholar +1 more source
Astrophysics and Space Science, 1994
Hydrodynamical calculations are becoming increasingly successful at understanding the shapes and kinematics of planetary nebulae (PNs). The most successful models are two-dimensional interacting stellar wind models for which the PN nucleus is assumed to originally expel much or most of its mass in an equatorial waistband.
openaire +2 more sources
Hydrodynamical calculations are becoming increasingly successful at understanding the shapes and kinematics of planetary nebulae (PNs). The most successful models are two-dimensional interacting stellar wind models for which the PN nucleus is assumed to originally expel much or most of its mass in an equatorial waistband.
openaire +2 more sources
CO in Planetary Nebulae and Proto-Planetary Nebulae
1997The evolution between the asymptotic giant branch (AGB) and the planetary nebula (PN) phases has long been a “missing link” in our understanding of stellar evolution. Through the study of cool IRAS sources, an increasing number of transition objects, or “proto-planetary nebulae”, has now been identified.
openaire +2 more sources
Symposium - International Astronomical Union, 1989
The object (α1950 = 18h04m.3; δ1950 = −8o56!4) was discovered in a 103a-E+RG 1 objective prism plate taken with the 92/67-cm Schmidt telescope of the Astrophysical Observatory of Asiago (Italy). It presents only the Hα emission and no stellar continuum; following Kohoutek (1965, 1969, 1972) it is a bona fide planetary nebula.
M. Turatto, F. Sabbadin, E. Capellaro
openaire +2 more sources
The object (α1950 = 18h04m.3; δ1950 = −8o56!4) was discovered in a 103a-E+RG 1 objective prism plate taken with the 92/67-cm Schmidt telescope of the Astrophysical Observatory of Asiago (Italy). It presents only the Hα emission and no stellar continuum; following Kohoutek (1965, 1969, 1972) it is a bona fide planetary nebula.
M. Turatto, F. Sabbadin, E. Capellaro
openaire +2 more sources
Synthesis of Organic Compounds in Planetary Nebulae and Proto-Planetary Nebulae
AIP Conference Proceedings, 2006Recent millimeter‐wave and infrared spectroscopic observations have found evidence of rapid synthesis of complex organic molecules in the late stages of stellar evolution. The chemical synthesis begins with the formation of acetylene, the first building block of benzene, in carbon stars.
openaire +3 more sources
Evolution of planetary nebulae
The Astronomy and Astrophysics Review, 1992A second argument in this direction was given by several astronomers in the 1950's. It had long been known from the double peaked emission lines observed in the nebulae, that they were expanding. The velocity of expansion is on the average 15 to 20 km s -t, with only exceptional cases differing by more than a factor 2 from this value.
openaire +2 more sources