What's the difference between lucubrate and lucubrator?

Lucubrate

Definition:

• (n.) To study by candlelight or a lamp; to study by night.
• (v. t.) To elaborate, perfect, or compose, by night study or by laborious endeavor.

Example Sentences:

• (1) Certainly, almost no one seriously addressing the subjects of place and memory – whether in fiction, film, photography or academia – now does so from beyond Sebald's shadow (his writerly camp followers are legion, immediately identifiable by their melancholy lucubrations, the black-and-white photographs that stud their paragraphs, their flourished fetishes for skulls and for silk …).

Lucubrator

Definition:

• (n.) One who studies by night; also, one who produces lucubrations.

Example Sentences:

• (1) Certainly, almost no one seriously addressing the subjects of place and memory – whether in fiction, film, photography or academia – now does so from beyond Sebald's shadow (his writerly camp followers are legion, immediately identifiable by their melancholy lucubrations, the black-and-white photographs that stud their paragraphs, their flourished fetishes for skulls and for silk …).