Assertion: nebula's structure | /r/CreatedBy | hot o-type star
Facets:
Source sentences:
text: It also includes a funnel-like or tornado-like structure caused by a hot O-type star that emanates ultraviolet light, heating and ionizing gases on the surface of the nebula.
text: It also includes a funnel-like structure caused by a hot O-type star that emanates ultraviolet light, heating and ionizing gases on the surface of the nebula.