Figure 1
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| Figure 2 | Figure 3 | Figure 4 | Figure 5 |
This image composite compares visible-light and infrared views from
NASA's Spitzer Space Telescope of the glowing Trifid Nebula, a giant
star-forming cloud of gas and dust located 5,400 light-years away in the
constellation Sagittarius.
Visible-light images of the Trifid taken with NASA's Hubble Space
Telescope, Baltimore, Md. (inside left, figure 1) and the National Optical
Astronomy Observatory, Tucson, Ariz., (outside left, figure 1) show a murky cloud
lined with dark trails of dust. Data of this same region from the
Institute for Radioastronomy millimeter telescope in Spain revealed four
dense knots, or cores, of dust (outlined by yellow circles), which are
"incubators" for embryonic stars. Astronomers thought these cores were
not yet ripe for stars, until Spitzer spotted the warmth of rapidly
growing massive embryos tucked inside.
These embryos are indicated with arrows in the false-color Spitzer
picture (right, figure 1), taken by the telescope's infrared array camera. The same
embryos cannot be seen in the visible-light pictures (left, figure 1). Spitzer
found clusters of embryos in two of the cores and only single embryos in
the other two. This is one of the first times that multiple embryos have
been observed in individual cores at this early stage of stellar
development.
