Assertion: nebula's spectrum | /r/HasProperty | continuous
Facets:
Source sentences:
text: They are divided into emission nebulas, whose spectra consist primarily of emission lines; reflection nebulas, which have a continuous spectrum with weak absorption lines; and dark nebulas, which are dense, nonluminous clouds of gas and dust that absorb the radiation of the bright background of the sky.
text: In the radio-frequency region of the spectrum, nebulas of this type emit a continuous thermal spectrum, recombination lines of H and He, and lines of, for example, OH and H 2 O that result from transitions between very high energy levels.