Sigma Orionis is just below Orion's Belt.
This is a young binary system consisting entirely of dwarf stars several million years old. Jim Kaler points out that only the AB orbit is stable; the others will eventually part the system. The whole system will end when the primary explodes, sending B out on its own (if it doesn't explode as well). The other components will dwindle and slowly expire as white dwarfs.
While the system as a whole goes under the binary label Struve 762, the AB component is actually BU 1032:
AB: 4.1, 5.3; 81º, 0.3".
AB-C: 3.8, 8.8; 240º, 10.7".
AB-D: 3.8, 6.6; 84º, 12.9".
AB-E: 3.8, 6.3; 62º, 41.3"
AB-F: 3.8, 7.9; 324º, 209.6".