Luke then learns from Obi - Wan 's spirit that he has a twin sister , whom he immediately realizes is Leia .
During his return trip to Dagobah , Luke hears a dying Yoda confirm that Vader is his father .
Luke then learns from Obi - Wan 's spirit that Luke has a twin sister , whom Luke immediately realizes is Leia .
During his return trip to Dagobah , Luke hears a dying Yoda confirm that Vader is his father .