Astronomy student of Sagan's at Cornell (3)

I believe the answer is:

nye

(Other definitions for nye that I've seen before include "Flock of pheasants" , "- - Bevan, 13 dn" , "Nickname of Aneurin Bevan" , "- Bevan, former Labour politician" , "Pheasant's nest" .)

I've seen this clue in The Washington Post.

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