A cluster of newborn stars herald their birth in this
interstellar Valentine’s Day commemorative picture obtained with NASA’s
Spitzer Space Telescope. These bright young stars are found in a
rosebud-shaped (and rose-colored) nebulosity known as NGC 7129. The star
cluster and its associated nebula are located at a distance of 3300
light-years in the constellation Cepheus.

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

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

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

The cold molecular cloud outside the bubble is mostly invisible in these
images. However, three very young stars near the center of the image are
sending jets of supersonic gas into the cloud. The impact of these jets
heats molecules of carbon monoxide in the cloud, producing the intricate
green 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 night
sky long ago,” said Megeath.

Not all stars are formed in clusters. Away from the main nebula and its
young 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 camera
that is sensitive to invisible infrared light at wavelengths that are about
ten times longer than visible light. In this four-color composite, emission
at 3.6 microns is depicted in blue, 4.5 microns in green, 5.8 microns in
orange, and 8.0 microns in red. The image covers a region that is about one
quarter the size of the full moon.

The NASA Jet Propulsion Laboratory (JPL) manages the Spitzer Space Telescope
mission for NASA’s Office of Space Science, Washington. Science operations
are conducted at the Spitzer Science Center at the California Institute of
Technology in Pasadena. JPL is a division of Caltech.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for
Astrophysics is a joint collaboration between the Smithsonian Astrophysical
Observatory and the Harvard College Observatory. CfA scientists, organized
into six research divisions, study the origin, evolution and ultimate fate
of the universe.

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