Helix Nebula, also known as The Helix, NGC 7293, is a large planetary
nebula (PN) located in the constellation Aquarius. Discovered by Karl
Ludwig Harding, probably before 1824, this object is one of the closest
to the Earth of all the bright planetary nebulae. The estimated distance
is about 215 parsecs or 700 light-years. It is similar in appearance to
the Ring Nebula, whose size, age, and physical characteristics are
similar to the Dumbbell Nebula, varying only in its relative proximity
and the appearance from the equatorial viewing angle.
The Helix Nebula has sometimes been referred to as the "Eye of God" in pop culture.
The Helix Nebula is an example of a planetary nebula, or 'planetary'
formed at the end of a star's evolution. Gases from the star in the
surrounding space appear, from our vantage point, as if we are looking
down a helix structure. The remnant central stellar core, known as a
planetary nebula nucleus or PNN, is destined to become a white dwarf
star. The observed glow of the central star is so energetic that it
causes the previously expelled gases to brightly fluoresce.
Helix Nebula in the constellation of Aquarius lies about 700
light-years away, spanning about 0.8 parsec or 2.5 light-years. Recent
images by the Hubble Space Telescope of the Helix Nebula are a composite
of newly released images from the ACS instrument and the wide-angle
images from the Mosaic Camera on the WIYN 0.9-metre telescope at Kitt
Peak National Observatory.
Currently, the age is estimated to be 10,600+2,300 −1,200 years, based solely upon a measured expansion rate of 31 km·s−1
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