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Name:
IC 418 - The "Spirograph" Nebula
Description: Planetary Nebula in the Milky
Way Galaxy
Position: R.A. 05h 27m 28.2s Dec. -12°
41' 50"
Constellation: Lepus
Image Credit: NASA and The Hubble Heritage
Team (STScI/AURA)
Mean
Surface Scale: The nebula is about 0.2 light-years or 13,000 AU
(18 arcseconds) in diameter
Distance: About 2000 light-years
Instrument: WFPC2
Exposure Date(s): February 1999 (F656N -
Sahai), September 1999
(F502N, F658N - Hajian)
Exposure Time: 35 minutes
Release
Date: September
7, 2000 1:00 a.m. (EDT)
Filters: Red: F658N [N II]Green: F656N HaBlue:
F502N [O III]
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ABOUT
THIS IMAGE:
Glowing like a multi-faceted
jewel, the planetary nebula IC 418 lies about 2,000 light-years from Earth
in the direction of the constellation Lepus. This photograph is one of
the latest from NASA's Hubble Space Telescope, obtained with the Wide
Field Planetary Camera 2.
A planetary nebula
represents the final stage in the evolution of a star similar to our Sun.
The star at the center of IC 418 was a red giant a few thousand years
ago, but then ejected its outer layers into space to form the nebula,
which has now expanded to a diameter of about 0.1 light-year. The stellar
remnant at the center is the hot core of the red giant, from which ultraviolet
radiation floods out into the surrounding gas, causing it to fluoresce.
Over the next several thousand years, the nebula will gradually disperse
into space, and then the star will cool and fade away for billions of
years as a white dwarf. Our own Sun is expected to undergo a similar fate,
but fortunately this will not occur until some 5 billion years from now.
The Hubble image of
IC 418 is shown in a false-color representation, based on Wide Field Planetary
Camera 2 exposures taken in February and September, 1999 through filters
that isolate light from various chemical elements. Red shows emission
from ionized nitrogen (the coolest gas in the nebula, located furthest
from the hot nucleus), green shows emission from hydrogen, and blue traces
the emission from ionized oxygen (the hottest gas, closest to the central
star). The remarkable textures seen in the nebula are newly revealed by
the Hubble telescope, and their origin is still uncertain.
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