Star Formation in Cassiopee - Star Formation in Cassiopeia - This star-forming region, called W5,...

Star Formation in Cassiopee - Star Formation in Cassiopeia - This star-forming region, called W5, is located approximately 6500 light years ago in the constellation Cassiopee. Several generations of stars appear on this cliche; the older ones are the blue stars in the centre of the two cavities; the younger stars are grouped at the edges of these cavities and at the ends of the gas pillars or they appear like pink dots; the white areas are home to the very young stars in formation. In this infrared image, heated dust appears in red, dense gas clouds appear in green. Composite image obtained by the Spitzer space telescope in 2006 and 2007. Generations of stars can be seen in this 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 pink dots at the tips of the elephant - trunk - like pillars. The white knotty areas are where the youngest stars are forming. Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. 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 sho