The Grand Design Spiral, NGC 3631, is located 53 million light-years away in the direction of the constellation Ursa Major in this view from NASA’s Hubble Space Telescope. Grand design spirals appear to have “arms” that wind around and into the galaxy’s centre.
A close examination of NGC 3631’s grand spiral arms reveals black dust lanes and luminous star-forming regions throughout the spiral arms’ inner reaches. The development of stars in spirals is like to traffic gridlock on the highway. Slower moving matter in the spiral’s disc causes a bottleneck, concentrating star-forming gas and dust in the inner half of their spiral arms, similar to cars on the highway. This swarm of stuff can become so dense that it collapses gravitationally, forming new stars (here seen in bright blue-white).
Data from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys was used to create the image. The colors blue and orange represent visible wavelengths of blue light and infrared light, respectively.