NASA / JPL-Caltech / CfA
This false-color image from the Spitzer Space Telescope shows
the main cloud of the Rho Ophiuchi star-forming region. Click on
the image for a wider, higher-resolution 9-megabyte photo.
One of our galaxy's closest star-forming regions provides the canvas for a glittering baby portrait from NASA's Spitzer Space Telescope. In the infrared image, infant stars nestle within the folds of a dusty hydrogen cloud around Rho Ophiuchi.
The Rho Ophiuchi nebula, a.k.a. Rho Oph ("row off"), is 407 light-years from Earth near the constellations Scorpio and Ophiuchus. In comparison, the well-known "Pillars of Creation" in the Eagle Nebula are 7,000 light-years away, while the star-forming Orion Nebula is about 1,500 light-years away.
"Rho Oph is a favorite region for astronomers studying star formation," Lori Allen of the Harvard-Smithsonian Center for Astrophysics, lead investigator for the new observations, said in a doubled-barreled news release from the Center for Astrophysics and the Spitzer team at NASA's Jet Propulsion Laboratory.
"Because the stars are so young, we can observe them at a very early evolutionary stage, and because the Ophiuchus molecular cloud is relatively close, we can resolve more detail than in more distant clusters, like Orion," she explained.
Just how young are those stars? Based on an analysis of the X-ray and infrared data, astronomers estimate that the median age is just 300,000 years, compared with our sun's age of about 4.6 billion years.
Rho Oph features a large main cloud of molecular hydrogen, known as Lynds 1688, which has been condensing to give birth to the hot young stars. Two long streamers trail off from the cloud in different directions.
In the color-coded Spitzer image you see above, the different hues reflect the relative temperatures and developmental stages of the various stars. The youngest stars are still shrouded by dust and show up in red. Older stars that have shed their baby blankets glitter in blue.
Spitzer's scientists say the extended white nebula that dominates the right side of the image is a region of the cloud that glows brighter in the infrared because its dust is being heated by bright young stars near the cloud's right edge. The most active star formation is taking place in a filament of cold, dense gas that shows up as a dark cloud in the image's lower left corner.