Eta Carinae

The Wikipedia article of the day for March 12, 2017 is Eta Carinae.
Eta Carinae is a stellar system of at least two stars with a combined luminosity over five million times that of the Sun, around 7500 light-years distant in the constellation Carina. First recorded as a 4th-magnitude star, it brightened considerably beginning in 1837 in an event known as the Great Eruption, becoming the second-brightest star in the sky between 11 and 14 March 1843 before fading well below naked eye visibility. It has been getting brighter again since about 1940, peaking above magnitude 4.5 in 2014. Eta Carinae is always above the horizon south of latitude 30°S, and never visible north of about latitude 30°N. The two main stars of the system orbit each other with a period of 5.54 years. The primary is a peculiar star similar to a luminous blue variable, initially 150–250 times as massive as the Sun but now at least 30 solar masses lighter, and is expected to eventually explode as a supernova. The secondary star is hot and also highly luminous, around 30–80 times as massive as the Sun. The system is heavily obscured by the Homunculus Nebula, material ejected from the primary during the Great Eruption.
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