W5 Star Formation Region
Ssc2008 15b

Credit: NASA/JPL-Caltech/L. Allen & X. Koenig (Harvard-Smithsonian CfA)

Observation • July 21st, 2008 • ssc2008-15b

ssc2008-15b

Generations of stars can be seen in this new infrared portrait from NASA's Spitzer Space Telescope. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Younger stars line the rims of the cavities, and some can be seen as dots at the tips of the elephant-trunk-like pillars. The white knotty areas are where the youngest stars are forming.

W5 spans an area of sky equivalent to four full moons and is about 6,500 light-years away in the constellation Cassiopeia. The Spitzer picture was taken over a period of 24 hours.

Like other massive star-forming regions, such as Orion and Carina, W5 contains large cavities that were carved out by radiation and winds from the region's most massive stars. According to the theory of triggered star-formation, the carving out of these cavities pushes gas together, causing it to ignite into successive generations of new stars.

This image contains some of the best evidence yet for the triggered star-formation theory. Scientists analyzing the photo have been able to show that the ages of the stars become progressively and systematically younger with distance from the center of the cavities.

This picture was taken with Spitzer's infrared array camera. It is a four-color composite, in which light with a wavelength of 3.6 microns is blue; 4.5-micron light is green; 5.8-micron light is orange; and 8-micron light is red.

About the Object

Name
W5IC 1848Soul Nebula
Type
Nebula > Type > Star Formation
Nebula > Appearance > Emission > H II Region
Distance
6,500 Light Years

Color Mapping

Band Wavelength Telescope
Infrared 3.6 µm Spitzer IRAC
Infrared 4.5 µm Spitzer IRAC
Infrared 5.8 µm Spitzer IRAC
Infrared 8.0 µm Spitzer IRAC

Astrometrics

Position (J2000)
RA =2h 54m 12.9s
Dec = 60° 26' 25.6"
Field of View
2.2 x 2.5 degrees
Orientation
North is 88.5° left of vertical