The Hubble Space Telescope has photographed the dying star IC 4406, which led to the formation of the Retina Nebula.
As part of the Hubble Legacy project, the space telescope’s website showed a photograph of IC 4406, a planetary nebula in the constellation Wolf, more than 5,000 light-years from Earth. It is a well-studied bipolar nebula in the southern sky. It is large enough and easy to study. The nebula was formed from the remnants of the dying star IC 4406 and is almost perfectly symmetrical – the left and right halves of the image are almost mirror images of each other.
The nebula’s material limits the intense radiation that emanates from the remnant of a dying star. The gas in IC 4406 is ionized by the light from the central star, and so the nebula glows brightly. In this image, the light from the oxygen atoms is colored blue; hydrogen is shown in green and nitrogen is shown in red. The color scale of the final image shows the difference in the concentration of these three gases in the nebula. The Hubble image does not show a large area of neutral gas, which does not emit visible light, but which can be seen with radio telescopes.
This image is part of Hubble’s second wide-angle planetary camera data in June 2001 by Bob O’Dell of Vanderbilt University and his collaborators, and in January 2002 by The Hubble Heritage Team.