In the quest to better understand the birth of stars and the formation
of new worlds, astronomers have used NASA's Spitzer Space Telescope to
examine the massive stars contained in a cloudy region called Sharpless
140. This cloud is a fascinating microcosm of a star-forming region since
it exhibits, within a relatively small area, all of the classic
manifestations of stellar birth.
Sharpless 140 lies almost 3000 light-years from Earth in the
constellation Cepheus. At its heart is a cluster of three deeply embedded
young stars, which are each several thousand times brighter than the Sun.
Though they are strikingly visible in this image from Spitzer's infrared
array camera, they are completely obscured in visible light, buried
within the core of the surrounding dust cloud.
The extreme youth of at least one of these stars is indicated by the
presence of a stream of gas moving at high velocities. Such outflows are
signatures of the processes surrounding a star that is still gobbling up
material as part of its formation.
The bright red bowl, or arc, seen in this image traces the outer
surface of the dense dust cloud encasing the young stars. This arc is
made up primarily of organic compounds called polycyclic aromatic
hydrocarbons, which glow on the surface of the cloud. Ultraviolet light
from a nearby bright star outside of the image is "eating away" at these
molecules. Eventually, this light will destroy the dust envelope and the
masked young stars will emerge.
This false-color image was taken on Oct. 11, 2003 and is composed of
photographs obtained at four wavelengths: 3.6 microns (blue), 4.5 microns
(green), 5.8 microns (orange) and 8 microns (red).
