CREATE TABLE "2901_3000" (
  "ngc_number" real,
  "object_type" text,
  "constellation" text,
  "right_ascension_j2000" text,
  "declination_j2000" text
);

Question: I want the NGC number for leo of irregular galaxy
SQL: SELECT "ngc_number" FROM "2901_3000" WHERE "constellation"='leo' AND "object_type"='irregular galaxy';

Question: Tell me the highest NGC number for right ascension of 09h40m28.5s
SQL: SELECT MAX("ngc_number") FROM "2901_3000" WHERE "right_ascension_j2000"='09h40m28.5s';

Question: What is the constellation for open cluster?
SQL: SELECT "constellation" FROM "2901_3000" WHERE "object_type"='open cluster';