what is the right ascension (j2000) when the apparent magnitude is 13?
CREATE TABLE "3001_3100" (
  "ngc_number" real,
  "object_type" text,
  "constellation" text,
  "right_ascension_j2000" text,
  "declination_j2000" text,
  "apparent_magnitude" real
);
SELECT "right_ascension_j2000" FROM "3001_3100" WHERE "apparent_magnitude"=13;