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Image Composite | Visible Light Image | Eagle Nebula Comparison |
This majestic false-color image from NASA's Spitzer Space Telescope shows
the "mountains" where stars are born. Dubbed "Mountains of Creation" by
Spitzer scientists, these towering pillars of cool gas and dust are
illuminated at their tips with light from warm embryonic stars.
The new infrared picture is reminiscent of Hubble's iconic visible-light
image of the Eagle Nebula, which also features a star-forming region,
or nebula, that is being sculpted into pillars by radiation and winds from
hot, massive stars. The pillars in the Spitzer image are part of a region
called W5, in the Cassiopeia constellation 7,000 light-years away and 50
light-years across. They are more than 10 times in the size of those in
the Eagle Nebula (shown to scale here).
The Spitzer's view differs from Hubble's because infrared light penetrates
dust, whereas visible light is blocked by it. In the Spitzer image,
hundreds of forming stars (white/yellow) can seen for the first time
inside the central pillar, and dozens inside the tall pillar to the left.
Scientists believe these star clusters were triggered into existence by
radiation and winds from an "initiator" star more than 10 times the mass
of our Sun. This star is not pictured, but the finger-like pillars "point"
toward its location above the image frame.
The Spitzer picture also reveals stars (blue) a bit older than the ones in
the pillar tips in the evacuated areas between the clouds. Scientists
believe these stars were born around the same time as the massive
initiator star not pictured. A third group of young stars occupies the
bright area below the central pillar. It is not known whether these stars
formed in a related or separate event. Some of the blue dots are
foreground stars that are not members of this nebula.
The red color in the Spitzer image represents organic molecules known as
polycyclic aromatic hydrocarbons. These building blocks of life are often
found in star-forming clouds of gas and dust. Like small dust grains, they
are heated by the light from the young stars, then emit energy in infrared
wavelengths.
This image was taken by the infrared array camera on Spitzer. It is a
4-color composite of infrared light, showing emissions from wavelengths
of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0
microns (red).
The image composite compares an infrared image taken by NASA's Spitzer
Space Telescope to a visible-light picture of the same region. While the
infrared view, dubbed "Mountains of Creation," reveals towering pillars of
dust aglow with the light of embryonic stars (white/yellow), the
visible-light view shows dark, barely-visible pillars. The added detail
in the Spitzer image reveals a dynamic region in the process of evolving
and creating new stellar life.
Why do the pictures look so different? The answer has two parts. First,
infrared light can travel through dust, while visible light is blocked by
it. In this case, infrared light from the stars tucked inside the dusty
pillars is escaping and being detected by Spitzer. Second, the dust making
up the pillars has been warmed by stars and consequently glows in infrared
light, where Spitzer can see it. This is a bit like seeing warm bodies at
night with infrared goggles. In summary, Spitzer is both seeing, and
seeing through, the dust.
The Spitzer image was taken by the infrared array camera on Spitzer. It is
a 4-color composite of infrared light, showing emissions from wavelengths
of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0
microns (red).
The visible-light image is from California Institute of Technology's
Digitized Sky Survey.