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Hubble Offers a Dazzling View of Necklace Nebula
By NASA’s Amazing Space reporters
Sept. 2011
A
Sun-like star’s last
gasps have caught the
eye of astronomers. They
used the Hubble Space Telescope
to view the Necklace Nebula, socalled because of its resemblance
to a piece of glittering jewelry.
The nebula consists of a bright
ring, measuring 12 trillion
miles wide and dotted with
pearls of glowing gas. The
object is the glowing remains
of an ordinary, Sun-like star,
called a planetary nebula.
What’s in a name?
The planetary nebula name is a
misnomer because these objects
have nothing to do with planets.
They acquired their name
more than 100 years ago when
astronomers looking through
small, crude telescopes saw them
as compact, round, green-colored
Continued, page 2…
IMAGE: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)
The Necklace Nebula: This Hubble image of the Necklace Nebula reveals a
glowing ring of gas that resembles a necklace. The bright dot in the center of the
ring is actually two stars orbiting close together. One of the stars is near the end of
its life and created the planetary nebula. The estimated age of the ring is around
5,000 years. The nebula is 15,000 light-years from Earth. Astronomers discovered
the nebula in November 2005 with the Isaac Newton Telescope during a survey of
planetary nebulas.
Continued from page 1…
A gallery of nebulas
objects that looked like the
planet Uranus.
A planetary nebula forms when a
dying star expels its outer layers
of material into space after it
runs out of fuel to sustain nuclear
reactions in its core. Our Sun will
undergo a similar process, but
not for another 5 billion years.
Planetary nebulas fade gradually
over tens of thousands of years.
The hot remains of the star’s
core will eventually cool off for
billions of years as a white dwarf.
These Hubble images show that planetary nebulas
come in many different shapes.
Cat’s Eye Nebula
Hourglass Nebula
Going out in style
Astronomers have used Hubble
to collect a rich assortment of
planetary nebulas. Many of
them, including the Cat’s Eye,
the Hourglass, the Helix, and
the Spirograph, have names that
describe their shapes. Planetary
nebulas are like snowflakes:
No two are exactly alike.
IMAGE: NASA, ESA, HEIC, and The Hubble
Heritage Team (STScI/AURA)
Helix Nebula
IMAGE: Raghvendra Sahai and John Trauger
(JPL), the WFPC2 science team, and NASA
Spirograph Nebula
Several ideas explain the diverse
shapes. One idea is that some
stars eject their material several
times at the end of their lives.
Another idea is that gravitational
interactions with companion stars
in two-star systems create some of
the intricate shapes.
The unique shapes are a work of
art that everyone can appreciate.
IMAGE: NASA, NOAO, ESA, the Hubble
Helix Nebula Team, M. Meixner (STScI),
and T.A. Rector (NRAO)
amazing-space.stsci.edu
2
IMAGE: NASA and The Hubble Heritage
Team (STScI/AURA)
SEE MORE Hubble images
and read more Star Witness
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students and teachers.
www.nasa.gov