Christine Pulliam
(617) 495-7463


CfA Press Release
 Release No.: 04-06
For Immediate Release: Thursday, February 12, 2004

Note to Editors: An image to accompany this release is online at:

Spitzer Space Telescope Photographs a Cosmic Valentine Rose

Cambridge, MA -- A cluster of newborn stars herald their birth in thisinterstellar Valentine's Day commemorative picture obtained with NASA'sSpitzer Space Telescope. These bright young stars are found in arosebud-shaped (and rose-colored) nebulosity known as NGC 7129. The starcluster and its associated nebula are located at a distance of 3300light-years in the constellation Cepheus.

A recent census of the cluster reveals the presence of 130 young stars. Thestars formed from a massive cloud of gas and dust that contains enough rawmaterials to create a thousand Sun-like stars. In a process that astronomersstill poorly understand, fragments of this molecular cloud became so coldand dense that they collapsed into stars. Most stars in our Milky Way galaxyare thought to form in such clusters.

"The diameter of the cluster is equal to the distance between the Sun andthe nearest star, Proxima Centauri. Within that distance, we find 130 stars.By combining data from the Smithsonian's MMT Telescope in Arizona withSpitzer data, we find that roughly half of these stars are surrounded bydisks of gas and dust. Each of these disks is a forming solar system," saidresearcher Tom Megeath (Harvard-Smithsonian Center for Astrophysics).

As in any nursery, mayhem reigns. Within the astronomically brief period ofa million years, the stars have managed to blow a large, irregular bubble inthe molecular cloud that once enveloped them like a cocoon. The rosy pinkhue is produced by glowing dust grains on the surface of the bubble beingheated by the intense light from the embedded young stars. Upon absorbingultraviolet and visible-light photons produced by the stars, the surroundingdust grains are heated and re-emit the energy at the longer infraredwavelengths observed by Spitzer. The reddish colors trace the distributionof molecular material thought to be rich in hydrocarbons.

The cold molecular cloud outside the bubble is mostly invisible in theseimages. However, three very young stars near the center of the image aresending jets of supersonic gas into the cloud. The impact of these jetsheats molecules of carbon monoxide in the cloud, producing the intricategreen nebulosity that forms the stem of the rosebud.

"The formation of our own solar system may have begun in a similar setting.Our Sun's siblings would have drifted away and disappeared into the nightsky long ago," said Megeath.

Not all stars are formed in clusters. Away from the main nebula and itsyoung cluster are two smaller nebulae, to the left and bottom of the central'rosebud,' each containing a stellar nursery with only a few young stars.

The Spitzer Space Telescope image was obtained with an infrared array camerathat is sensitive to invisible infrared light at wavelengths that are aboutten times longer than visible light. In this four-color composite, emissionat 3.6 microns is depicted in blue, 4.5 microns in green, 5.8 microns inorange, and 8.0 microns in red. The image covers a region that is about onequarter the size of the full moon.

The NASA Jet Propulsion Laboratory (JPL) manages the Spitzer Space Telescopemission for NASA's Office of Space Science, Washington. Science operationsare conducted at the Spitzer Science Center at the California Institute ofTechnology in Pasadena. JPL is a division of Caltech.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center forAstrophysics is a joint collaboration between the Smithsonian AstrophysicalObservatory and the Harvard College Observatory. CfA scientists, organizedinto six research divisions, study the origin, evolution and ultimate fateof the universe.

For more information, contact:

David Aguilar, Director of Public Affairs
Harvard-Smithsonian Center for Astrophysics
Phone: 617-495-7462 Fax: 617-495-7468

Christine Pulliam
Public Affairs Specialist
Harvard-Smithsonian Center for Astrophysics
Phone: 617-495-7463, Fax: 617-495-7016

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