光ひかりエコーMeanings1nounlight echophysicsAstrophysical phenomenon where light from a stellar explosion or flare is reflected by interstellar dust, arriving later and appearing as an echo.超ちょう新しん星せい爆ばく発はつの後あと、光ひかりエコーが観かん測そくされた。After the supernova explosion, a light echo was observed.
