Castor A and B are a binary star system with a period of 467 years, and a separation of about 6.8 arcseconds ( 90 AU). Each of these two stars is, itself a binary star system. Castor A consists of two stars separated by 4 million miles ( 0.05 AU) with a period of 9.2 days. Castor B are a pair of stars with a period of 2.9 days and a separation of less than 3 million miles. At a distance of 72 arcseconds away (1000 AU) and a period exceeding 10,000 years, is Castor C, also called YY Geminorium, which is itself a binary star system with a period of 19 hours and a separation of 1.7 million miles.
A scale model of this system would have Castor C at 4500 feet, A-B separated by 340 feet, and the individual pairs of stars separated by about 2 inches each!