What type of astronomical object is Eta Carinae classified as?

Eta Carinae is classified as a variable star system, specifically a massive binary star system located in the Carina constellation. This classification is accurate due to its fluctuating brightness, which is characteristic of variable stars. The light output of Eta Carinae changes significantly over time due to interactions between the two stars in the system, as well as due to changes in the surrounding nebula.

Eta Carinae is particularly well-known for its historical outbursts, notably one that occurred in the mid-19th century when it dramatically increased in brightness, earning it the title of one of the most luminous stars in the Milky Way. Observations have revealed that one of the stars in the system is a very massive and luminous O-type star, while the other is likely a smaller, less massive companion, contributing to the system's variability.

The other classifications do not apply to Eta Carinae. It is not a black hole, as it is composed of visible, massive stars. Additionally, it does not represent a globular cluster, which refers to tightly bound groups of stars orbiting the nucleus of a galaxy. Finally, it is not a neutron star, which is the remnant of a supernova explosion, characterized by extremely high density