GODDARD SPACE FLIGHT CENTER, June 8 -- The Hubble Space Telescope has produced images that show gas shells being ejected into space at regular intervals by an unusual type of white dwarf star. These images may shed light on the role that novae play in the evolution of our galaxy, including their influence on the distribution of heavier elements and the development of planetary systems. The images were produced by the Hubble Space Telescope's Near Infrared Camera Multi-Object Spectrograph (NICMOS). They are the first images of gas shells produced by novae that are members of a class of double star systems called Cataclysmic Variables. The images may provide important data for use in testing the accuracy of some key theories concerning novae and galactic evolution. In analyzing the images, the team of scientists that released the images plans to compare the ejected shells in the images to computer simulations of nova explosions. Studies of these novae will be critical in improving our calculations and will help us better understand the cause and evolution of these explosions, said team member Sumner Starrfield from Arizona State University.