Eta Carinae, formerly known as Eta Argus, is a stellar system containing at least two stars with a combined luminosity greater than five million times that of the Sun, located around 7,500 light-years distant in the constellation Carina. Previously a 4th-magnitude star, it brightened in 1837 to become brighter than Rigel, marking the start of its so-called "Great Eruption". It became the second-brightest star in the sky between 11 and 14 March 1843 before fading well below naked-eye visibility after 1856. In a smaller eruption, it reached 6th magnitude in 1892 before fading again. It has brightened consistently since about 1940, becoming brighter than magnitude 4.5 by 2014.
The Homunculus Nebula, surrounding Eta Carinae, imaged by WFPC2 at red and near-ultraviolet wavelengths Credit: Jon Morse (University of Colorado) & NASA Hubble Space Telescope
Eta Carinae and Carina Nebula in the constellation of Carina
Hubble Space Telescope composite of Eta Carinae showing the unusual emission spectrum (near-IR image spectrum from the Hubble Space Telescope Imaging Spectrograph CCD)
Stars similar to Eta Carinae in nearby galaxies
Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was the southern foundation of the larger constellation of Argo Navis until it was divided into three pieces, the other two being Puppis, and Vela.
The constellation Carina as it can be seen by the naked eye
