The Nature of Eta Carinae

Eta Carinae is the most massive and luminous star in our part of the Milky Way galaxy. It is a naked-eye object visible to observers in the southern hemisphere and the tropics. In the 1840's it briefly became the second brightest star in the sky. During this "great eruption," its total energy output rivaled that of a supernova as it ejected a shell containing several times the mass of the Sun and survived. Today we see that ejecta as the bipolar "Homunculus" nebula enshrouding the star itself.