At the Edge of the Helix Nebula
Credit: R. O'Dell and K. Handron
(Rice University),
NASA
While exploring the inner edge of the
Helix Nebula with the
Hubble Space Telescope's
Wide Field Planetary Camera 2,
astronomers were able to produce
this striking image - rich in details of an exotic environment.
This planetary nebula, created near the final phase of a sun-like
star's life, is composed of
tenuous shells of gas ejected by the
hot central star.
The atoms of gas, stripped of
electrons by
ultraviolet radiation from the central star,
radiate light at characteristic energies allowing specific
chemical elements to be identified.
In this image, emission from
nitrogen is represented as red,
hydrogen emission as green, and
oxygen as blue.
The inner edge of the
Helix Nebula, also known as NGC 7293, is in the direction toward
the central star, which is toward the upper right.
Clearly visible near the inner edge are finger shaped
cometary knots.