Eta Carinae Light Echo

These images reveal light from a massive stellar outburst in the Carina Nebula reflecting off dust clouds surrounding a behemoth double-star system.

The color image at left shows the Carina Nebula, a star-forming region located 7,500 light-years from Earth. The massive double-star system Eta Carinae resides near the top of the image. The star system, about 120 times more massive than the Sun, produced a spectacular outburst that was seen on Earth from 1837 to 1858.

But some of the light from the eruption took an indirect path and is just now reaching our planet. The light bounced off dust clouds (the boxed region about 100 light-years away at the bottom of the image) and was rerouted to Earth, a phenomenon called a light echo. The image was taken in February 2000 by the U.S. National Optical Astronomy Observatory's Curtis Schmidt Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile.

The three black-and-white images at right show light from the eruption illuminating dust clouds near the doomed star system as it moves through them. The effect is like shining a flashlight on different regions of a vast cavern. The images were taken over an eight-year span by the U.S. National Optical Astronomy Observatory's Blanco 4-meter telescope at the CTIO.

About the colours

Blue: oxygen Green: hydrogen Red: sulfur

About the data

The science team studying the Eta Car light echo was led by A. Rest (STScI). The color image (left) of a portion of the Carina Nebula was taken with the CTIO Curtis Schmidt telescope on February 25, 2000. The filter and color assignments are as follows: oxygen (blue), hydrogen (green), and sulfur (red). The single-filter images of the light echo (below right) were taken in 2003, 2010, and 2011 with the CTIO 4-m Blanco telescope.