Carina nebula
"Trumpler 16 is an open cluster that contains the massive luminous blue variable Eta Carinae, one of the brightest stars in the galaxy. It is possibly as much as 120 times the mass of the Sun, and emits the light of 4,000,000 Suns. Eta Carinae is nearing the end of its life, and is surrounded by a huge nebula, cast off by numerous eruptions of the star over the last several centuries. It is expected to explode into a supernova at any time. Trumpler 14 (annotated) contains the huge double star HD 93129 A/B. The young O3 class star HD 93129 A is one of the brightest stars in the galaxy that is still on the main sequence, and with a luminosity equivalent to 3,000,000 Suns. It is very nearly as bright as Eta Carinae, but this is not obvious in the photo due to obscuring nebulosities".