Name the competition of panathinaikos
CREATE TABLE "table1_17594659_1" (
  "season" text,
  "competition" text,
  "round" text,
  "opposition" text,
  "first_leg" text,
  "second_leg" text,
  "aggregate" text
);
SELECT "competition" FROM "table1_17594659_1" WHERE "opposition"='Panathinaikos';