This is the first of two views of Nova Cygni 1992, an eruption in a binary star system located about 10,000 light years from Earth. The nova was discovered in the constellation Cygnus on February 19, 1992. This image was taken on May 31, 1993. The exploding star has expelled a bubble of gas. It appears bightest around its periphery where we are looking through the greatest thickness of gas. It gives the impression that the formation is like a ring, or hula-hoop, but in reality it is probably shaped more like a squashed ball. A bar of light that appears to run diagonally from upper left to lower right across the shell is unexpected and difficult to explain. This image was taken before the first servicing Mission in 1994 and it is hard to distinguish fine details close to the bright central star due to the distorting effect of the spherical aberration in the main telescope mirror.
Camera: Faint Object Camera
Credit: F. Paresce (STScl and ESA), NASA, and ESA