Hubble probes history of dying star

One of the most-complex planetary nebulae ever seen, NGC 6543, or the "Cat`s Eye Nebula," is estimated to be around 1000 years old. According to NASA/Space Telescope Science Institute researchers, who presented this image at the American Astronomical Society meeting in Tucson, AZ, in January, the nebula is a visual "fossil record" of the dynamics and late evolution of a dying star. The observed "cocoon" is created as the star loses outer layers of gas.

Mar 1st, 1995

Hubble probes history of dying star

Heather W. Messenger

One of the most-complex planetary nebulae ever seen, NGC 6543, or the "Cat`s Eye Nebula," is estimated to be around 1000 years old. According to NASA/Space Telescope Science Institute researchers, who presented this image at the American Astronomical Society meeting in Tucson, AZ, in January, the nebula is a visual "fossil record" of the dynamics and late evolution of a dying star. The observed "cocoon" is created as the star loses outer layers of gas.

Red, blue, and green images, taken with Wide Field Planetary Camera-2 on the Hubble Telescope, were combined to produce the photo. NGC 6543 is 3000 light years away in the northern constellation Draco. A preliminary interpretation suggests that the star might actually be a double star (too close to be resolved by Hubble and appearing as a single point of light in the center). The intricate structures seen are more complex than those of most planetary nebulae and could be explained by dynamical effects of two stars orbiting one another. According to this model, a "stellar wind" of gas blown off the central star created the elongated shell of dense, glowing gas that is embedded inside two larger lobes of gas blown off at an earlier phase. These lobes are "pinched" by a ring of denser gas.

The suspected companion star might also be responsible for a pair of high-speed gas jets that lie at right angles to the equatorial ring and produce the bright arcs near the lobe edges. Wobbling or precessing of the jets because they point in different directions may indicate they are turning off and on as the nebula decays.

More in Optics