Invisible Giants Exposed in New Spitzer Image
April 13, 2004
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
http://www.spitzer.caltech.edu and
http://photojournal.jpl.nasa.gov/catalog/PIA05736.
"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 occurs.
Launched on August 25, 2003, from Cape Canaveral, Florida,
the Spitzer Space Telescope is the fourth of NASAs 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 at http://www.spitzer.caltech.edu.
