Hubble Photographs a Planetary Nebula to Commemorate Decommissioning of Super Camera
The Hubble community bids farewell to the soon-to-be decommissioned Wide Field Planetary Camera 2 (WFPC2) onboard the Hubble Space Telescope. In
tribute to Hubble's longest-running optical camera, a planetary nebula has been
imaged as WFPC2's final "pretty picture."
This planetary nebula is known as Kohoutek 4-55 (or K 4-55). It is one of a series
of planetary nebulae that were named after their discoverer, Czech astronomer
Lubos Kohoutek. A planetary nebula contains the outer layers of a red giant star
that were expelled into interstellar space when the star was in the late stages of
its life. Ultraviolet radiation emitted from the remaining hot core of the star ionizes
the ejected gas shells, causing them to glow.
In the specific case of K 4-55, a bright inner ring is surrounded by a bipolar
structure. The entire system is then surrounded by a faint red halo, seen in the
emission by nitrogen gas. This multi-shell structure is fairly uncommon in
This Hubble image was taken by WFPC2 on May 4, 2009. The colors
represent the makeup of the various emission clouds in the nebula: red
represents nitrogen, green represents hydrogen, and blue represents oxygen.
K 4-55 is nearly 4,600 light-years away in the constellation Cygnus.
The WFPC2 instrument, which was installed in 1993 to replace the original Wide
Field/Planetary Camera, will be removed to make room for Wide Field Camera 3
during the upcoming Hubble Servicing Mission.
During the camera's amazing, nearly 16-year run, WFPC2 provided outstanding
science and spectacular images of the cosmos. Some of its best-remembered
images are of the Eagle Nebula pillars, Comet P/Shoemaker-Levy 9's impacts on
Jupiter's atmosphere, and the 1995 Hubble Deep Field -- the longest and deepest
Hubble optical image of its time.
The scientific and inspirational legacy of WFPC2 will be felt by astronomers and
the public alike, for as long as the story of the Hubble Space Telescope is told.
WFPC2 was developed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif.
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Acknowledgment: R. Sahai and J. Trauger (Jet Propulsion Laboratory)