The image of Supernova 1987A at the left shows the star system as it looked in 1994. To the right is a recent image taken by the Hubble in 1997. The bulging knot of gas (arrow), which dangles into the ring like a stalactite, is beginning to glow bright yellow as the leading edge of the shockwave crashes into it. Astronomers expect that the entire ring will light up over the next few years.
The material in the center of both images is the visible part of the shredded star, rushing outward at 3,000 kilometers per second. It contains iron and other heavy elements and is visible because it is heated by radioactive elements created in the supernova explosion. The bright dot in the lower left is a nearby star, which is not physically part of the system.