CREATE TABLE table_70613 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" FLOAT)

Who is the opponent on September 9, 1979?
SELECT "Opponent" FROM table_70613 WHERE "Date" = 'september 9, 1979'
SELECT "Opponent" FROM "table_70613" WHERE "Date" = 'september 9, 1979'