Assertion: nebula's material | /r/HasProperty | 10 km/s
Facets:
Source sentences:
text: These hot stars are also source of fast stellar winds (order 1,000 km/s), outflowing material which is rammed into and colliding and interacting with the material of the shell, which is expanding at the much slower rate of the old wind of the Red Giant phase (order 10 km/s).