NGC 246 (also known as the Skull Nebula or Caldwell 56) is a planetary nebula in the constellation Cetus. The nebula and the stars associated with it are listed in several catalogs, as summarized by the SIMBAD database. It is roughly 1,600 light-years away. The nebula's central star is the 12th magnitude white dwarf HIP 3678. It is not to be confused with the Rosette Nebula (NGC 2337), which is also referred to as the "Skull."