This is the 1079th most frequent Japanese word.
消え
"消え" means "disappear" or "vanish."
In this sentence, "消えた" indicates that the candle's flame extinguished due to the wind.
蝋燭の火が風で消えた。
The candle's flame went out due to the wind.
Here, "消えた" is used to indicate that her smile vanished or was no longer visible.
彼女の笑顔が急に消えた。
Her smile suddenly disappeared.
In this context, "消えていった" shows a gradual disappearance of the stars from view.