Assertion: nebula's gas | /r/HasProperty | ionized
Facets:
value: mostly
type: DEGREE
value: usually
type: DEGREE
Source sentences:
text: Usually the gases in an emission nebula are ionized.
text: Visible light nebulae may be divided into emission nebulae, which emit spectral line radiation from excited or ionized gas (mostly ionized hydrogen); they are often called H II regions, H II referring to ionized hydrogen), and reflection nebulae which are visible primarily due to the light they reflect.
text: Usually the gases in an emission nebula are ionized.
text: These nebulae are also called HII regions, with the "H" standing for hydrogen and the "II" indicating that the gas is ionized.
text: The nebula has a mass 2,000 times that of the Sun and contains associations of stars, reflection nebulae, neutral clouds of dust and gas, and ionized gas.
text: Emission nebulae emit spectral line radiation from ionized gas (mostly ionized hydrogen); they are often called HII regions (the term "HII" is used in professional astronomy to refer to ionized hydrogen).