Assertion: nebula's material | /r/HasProperty | expelled by the star
Facets:
value: long ago
type: TEMPORAL
Source sentences:
text: The faint, scallop-shaped material surrounding the ring was expelled by the star during the early stages of the planetary nebula formation.
text: This mechanism is responsible for the glow of the denser, inner parts of the nebula, but also of the periphery, the nebular halo, corresponding to material expelled by the star long ago as stellar wind.