The term proto-planetary nebulae (PPNe) in the context of the late stages of stellar evolution was created only slightly more than 20 years ago to express the belief that in the near future these objects will become planetary nebulae (PNe). The first proto-planetary nebulae (called...
The term proto-planetary nebulae (PPNe) in the context of the late stages of stellar evolution was created only slightly more than 20 years ago to express the belief that in the near future these objects will become planetary nebulae (PNe). The first proto-planetary nebulae (called...