- A
protoplanetary nebula or
preplanetary nebula (PPN,
plural PPNe) is an
astronomical object which is at the short-lived
episode during a star's
rapid evolution...
-
about 12 billion
years after its formation. A
protoplanetary nebula or
preplanetary nebula (PPN,
plural PPNe) is an
astronomical object which is at the short-lived...
- IRAS 13208-6020 is a
preplanetary nebula in the
Constellation Centaurus.
These nebulae are
formed from
material that is shed by a
central star. It was...
-
surrounded by a pinwheel-shaped nebula, IRAS 23166+1655,
thought to be a
preplanetary nebula. It is a
binary system that
includes an
extreme carbon star. The...
- star SAO 244567.
Until the
early 1970s, it was
observed on
Earth as a
preplanetary nebula in
which the gas had not yet
become hot and ionized. The image...
- Strasbourg.
Retrieved 2007-01-05. "Hubble
Images Searchlight Beams from a
Preplanetary Nebula". ESA/Hubble
Picture of the W****.
Retrieved 24
April 2012. Hrivnak...
- Morris, Mark; Reipurth, Bo (April 1990), "The
optical form of the
bipolar preplanetary nebula IRAS 09371 + 1212",
Publications of the
Astronomical Society of...
- Contreras, Carmen; Morris, Mark; Claussen, Mark (2007). "A
Quadrupolar Preplanetary Nebula: IRAS 19475+3119". The
Astrophysical Journal. 658 (1): 410–422...
