Westbrook Nebula
Encyclopedia
Westbrook Nebula is an aspherical
protoplanetary nebula
. It is being formed by a star that has passed through the red giant
phase and has ceased nuclear fusion at its core. This star is concealed at the center of the nebula, and is ejecting gas and dust at velocities of up to 200 km/s. The nebula is named after William E. Westbrook, who died in 1975.
This nebula began to form about 200 years ago, and primarily consists of molecular gas. The outer part of the nebula is the result of interaction between rapid bi-polar outflow and the gas that was ejected when the star was passing through its asymptotic giant branch
phase. The lobes are inclined about 24° to the line of sight. The energy being radiated
from the nebula consists of scattered light from the star at the core, light being emitted from a compact HII region surrounding the star, and energy from the shock-excited gas in the lobes.
The core star is believed to be of spectral class B0 and has 12,200 times the solar luminosity.
protoplanetary nebula
Protoplanetary nebula
A protoplanetary nebula or preplanetary nebula is an astronomical object which is at the short-lived episode during a star's rapid stellar evolution between the late asymptotic giant branch phase and the subsequent planetary nebula phase. A PPN emits strongly in infrared radiation, and is a...
. It is being formed by a star that has passed through the red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
phase and has ceased nuclear fusion at its core. This star is concealed at the center of the nebula, and is ejecting gas and dust at velocities of up to 200 km/s. The nebula is named after William E. Westbrook, who died in 1975.
This nebula began to form about 200 years ago, and primarily consists of molecular gas. The outer part of the nebula is the result of interaction between rapid bi-polar outflow and the gas that was ejected when the star was passing through its asymptotic giant branch
Asymptotic Giant Branch
The asymptotic giant branch is the region of the Hertzsprung-Russell diagram populated by evolving low to medium-mass stars. This is a period of stellar evolution undertaken by all low to intermediate mass stars late in their lives....
phase. The lobes are inclined about 24° to the line of sight. The energy being radiated
from the nebula consists of scattered light from the star at the core, light being emitted from a compact HII region surrounding the star, and energy from the shock-excited gas in the lobes.
The core star is believed to be of spectral class B0 and has 12,200 times the solar luminosity.