Search for ionized cores in proto-planetary nebulae, and the asymptotic giant branch to planetary nebula transition

Abstract

view Abstract Citations (18) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Search for Ionized Cores in Proto--Planetary Nebulae, and the Asymptotic Giant Branch to Planetary Nebula Transition Kaeufl, Hans U. ; Renzini, Alvio ; Stanghellini, Letizia Abstract Preliminary evaluations are made of the time taken by the circumstellar dust shells to become optically thin at visible and near-IR wavelengths, following the termination of the superwind envelope ejection. The typical thinning times are estimated at 1000 and 100 yr at H-alpha and Br-alpha wavelengths, respectively. Results of observations are then presented for a sample of candidate transition objects. The results imply transition times in excess of 1000 yrs for most post-AGB stars, and therefore the transition time may be comparable to the nebular age in a fair fraction of known planetary nebulae. Publication: The Astrophysical Journal Pub Date: June 1993 DOI: 10.1086/172741 Bibcode: 1993ApJ...410..251K Keywords: Asymptotic Giant Branch Stars; Planetary Nebulae; Protoplanets; Stellar Cores; Stellar Evolution; Hydroxyl Emission; Interstellar Extinction; Stellar Envelopes; Stellar Spectrophotometry; Astrophysics; ISM: PLANETARY NEBULAE: GENERAL; STARS: CIRCUMSTELLAR MATTER; STARS: EVOLUTION; STARS: INTERIORS full text sources ADS | data products SIMBAD (16)