A dying star on the verge of exploding creates a cosmic "butterfly" in a new picture from Hubble's WFC3. The central star, now obscured by a dense band of dust, was once five times the mass of the sun. Over the past two thousand years the star has expelled most of its outer gas envelope to create the ghostly "wings," which together span about two light-years.
Known as a planetary nebula, this structure lies roughly 3,800 light-years away. Optical filters in the space telescope allowed astronomers to precisely determine the nebula's chemical makeup, temperature, and density, and to trace the stages of the star's demise.
"Hubble's new camera and spectrograph propel us forward into a new beginning for astronomy and astrophysics," Heidi Hammel, a Hubble research scientist at the Space Science Institute in Boulder, Colorado, said during a September 9, 2009, press conference.
Image courtesy NASA, ESA, and the Hubble SM4 ERO Team