Eta Carinae: a massive binary system

Eta Carinae is an exceptionally luminous, massive binary star system. Older NASA materials gave it about 150 solar masses and a luminosity around four million Suns. More recent estimates distinguish the system’s components and report different values: for example, NASA describes the primary star as about 90 solar masses and the system’s luminosity as about five million Suns. The numbers therefore depend on the source, date, and what is being measured.