Results 211 to 218 of about 7,989 (218)
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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.
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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
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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
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Planetary nebulae and ALMA [PDF]
Astrophysics and Space Science, 2007 Our understanding of the late evolution of intermediate mass stars (∼1–8M⊙) through the planetary nebula phase is undergoing major developments. Observations at infrared and millimeter wavelengths have revealed important components of neutral gas and dust in the nebulae that directly trace their formation from mass-loss on the Asymptotic Giant Branch ...
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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.
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