Press Release

Invisible Giants Exposed in New NASA Spitzer Image

By SpaceRef Editor
April 13, 2004
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Hidden behind a curtain of dusty darkness lurks one of the most
violent pockets of star birth in our galaxy. Called DR21, this stellar
nursery is so draped in cosmic dust that it appears invisible to the
human eye.

By seeing in the infrared, NASA’s Spitzer Space Telescope has pulled
this veil aside, revealing a fireworks-like display of massive stars.
The biggest of these stars is estimated to be 100,000 times as bright
as our own Sun.

The new image is available online at


"We’ve never seen anything like this before," said Dr. William Reach,
an investigator for the latest observations and an astronomer at the
Spitzer Science Center, located at the California Institute of
Technology, Pasadena, Calif. "The massive stars are ripping the cloud
of gas and dust around them to shreds." The principal investigator is
Dr. Anthony Marston, a former Spitzer astronomer now at the European
Space Research and Technology Centre, the Netherlands.

Located about 10,000 light-years away in the Cygnus constellation of
our Milky Way galaxy, DR21 is a turbulent nest of giant newborn stars.
The region is buried in so much space dust that no visible light
escapes it. Previous images taken with radio and near-infrared bands
of light reveal a powerful jet emanating from a huge, nebulous cloud.
But these views are just the tip of the iceberg.

Spitzer’s highly sensitive infrared detectors were able to see past
the obscuring dust to the stars behind. The new false-color image
spans a vast expanse of space, with DR21 at the top center. Within
DR21, a dense knot of massive stars can be seen surrounded by a wispy
cloud of gas and dust. Red filaments containing organic compounds
called polycyclic aromatic hydrocarbons stretch horizontally and
vertically across this cloud. A green jet of gas shoots downward past
the bulge of stars and represents fast-moving, hot gas being ejected
from the region’s biggest star.

Below DR21 are distinct pockets of star formation, never captured in
full detail before. The large swirling cloud to the lower left is
thought to be a stellar nursery like DR21’s, but with smaller stars. A
bubble possibly formed by a past generation of stars is visible within
the lower rim of this cloud.

The new view testifies to the ability of massive newborn stars to
destroy the cloud that blankets them. Astronomers plan to use these
observations to determine precisely how such an energetic event

Launched on August 25, 2003, from Cape Canaveral, Florida, the Spitzer
Space Telescope is the fourth of NASA’s Great Observatories, a program
that also includes the Hubble Space Telescope, Compton Gamma Ray
Observatory and Chandra X-ray Observatory.

JPL manages the Spitzer Space Telescope mission for NASA’s Office of
Space Science, Washington. Science operations are conducted at the
Spitzer Science Center. JPL is a division of Caltech. Spitzer’s
infrared array camera, used to capture the new image of DR21, was
built by NASA Goddard Space Flight Center, Greenbelt, Md. The
development of the camera was led by Dr. Giovanni Fazio of Smithsonian
Astrophysical Observatory, Cambridge, Mass.

Additional information about the Spitzer Space Telescope is available

SpaceRef staff editor.