ちょう新星 しんせい爆発 ばくはつではありませんでした
chōshin sei bakuhatsudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 超新星爆発

1. Was not a supernova.; It was not a supernova.

Past/Perfective
Negative
Polite
Formal Register
Astronomy