CREATE TABLE table_11440 ("NGC number" FLOAT, "Object type" CLOB, "Constellation" CLOB, "Right ascension  (  J2000  ) " CLOB, "Declination  (  J2000  ) " CLOB)

What Constellation has a 20h56m40s Right Ascension (J2000)?
SELECT "Constellation" FROM table_11440 WHERE "Right ascension ( J2000 )" = '20h56m40s'
SELECT "Constellation" FROM "table_11440" WHERE "Right ascension ( J2000 )" = '20h56m40s'