NGC 225 is an open cluster in the constellationCassiopeia. It is located roughly 2,200 light-years from Earth. It is about 100 to 150 million years old.[2]
The binary fraction, or the fraction of stars that are multiple stars, is 0.52.[2]
^R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN978-0-933346-51-2.