Invited_talk abstract details

Planetary nebulae (PN) were first discovered over 200 years ago and our understanding of these objects has undergone significant evolution over the years. Developments in astronomical optical spectroscopy and atomic physics have shown that PN are gaseous objects photoionized by UV radiation from a hot central star. Studies of the kinematics of the nebulae coupled with progress in theories of stellar evolution have led to the identification that PN are evolved stars and progenitors of white dwarfs. Development of infrared and millimeter-wave technology in the 1970s made us realize that there are significant amount of neutral matter (molecules and dust) in PN. The link of PN to the stellar winds from their progenitor AGB stars and subsequent dynamical interactions are now believed to be the underlying causes of the morphological structures of PN. The role of PN as prolific molecular factories producing complex molecules and organic solids has significant implications on the chemical enrichment of the Galaxy.

In this talk, we will emphasize the misconceptions and errors that we have encountered in our journey of understanding the nature of PN. The various detours and dead ends that had happened during our quest to pin down the evolutionary status and causes of nebulae ejection will be discussed. As there are still many unsolved problems in PN research, these lessons of history have much to offer for future progress in this field.