η Car is a good example of how some astrophysical objects are far from well understood. It is a remarkably well-studied star, yet as astronomers come up with explanations for modern observations, they open a comparable amount of new questions.
Eta is an extraordinary object. It is extreme in its parameters (among the most luminous, most massive stars we know of, it has the brightest know stellar wind at mm wavelengths, and an elegant bipolar nebula). It unites multiple points of interest in astrophysics: stellar physics (instability and the Eddington limit), stellar evolution (extreme case of LBV), gas dynamics (in the bipolar flows of the Nebula), and the prospect of going hypernova, among others
I hope this blog was useful in highlighting some of the particularities and surprising features of Eta Carinae. I hope it has at least done the star some justice in how interesting it is!