determiner
Yes, sunset can be considered as indirect energy as it represents the dissipation of solar energy accumulated throughout the day. The colors we see during sunset are a result of the scattering of sunlight by the Earth's atmosphere, which is a form of energy transfer.
Aurora is a noun.
Eyepiece is a noun.
Sky is a noun. It can be use as a subject.
Sunset is a noun.
"Night" is a noun. It refers to the period of darkness between sunset and sunrise.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "twirl" is a verb.
The part of speech for "explicit" is an adjective.
The part of speech for "indefinite" is an adjective.