ちょう新星 しんせい残骸 ざんがいじゃなかったです
chōshin sei zangaijanakattadesu

Noun
Desu Copula

The polite, past negative form of 超新星残骸

1. Wasn't a supernova remnant.

Past/Perfective
Negative
Polite
Casual Register
Astronomy