Green sub-constellation _ What constellation is green sub?

What constellation is "I" in the Norwegian forest?

Norwegian Forest mainly tells the story of the protagonist's struggle between Naoko, who is emotionally unstable and mentally ill, and Kobayashi Midoriko, who is cheerful and lively, and starts a journey of self-growth. Summary: Watanabe's first love Naoko was originally the girlfriend of his high school friend Muyue, but later Muyue committed suicide and Naoko lived alone. A year later, Watanabe and Naoko got along skillfully.