Assertion: helium | /r/HasProperty | confirmed by french astronomer
Facets:
value: subsequently
type: TEMPORAL
Source sentences:
text: It was first detected as an unknown, yellow spectral line signature in sunlight, during a solar eclipse in 1868 by Georges Rayet, Captain C. T. Haig, Norman R. Pogson, and Lieutenant John Herschel, and was subsequently confirmed by French astronomer, Jules Janssen.