A Broad Spectrum Pinwheel

When I worked in the audio business, we used to jokingly describe a wide band system as working from dc to daylight. This picture of the M101 (aka, the Pinwheel Galaxy) uses images take in the infrared, visible, ultraviolet and X-rays from four of NASA’s space-based telescopes. The wide-spectrum view shows that both young and old stars are evenly distributed along the galaxy’s spiral arms. Composite images allow astronomers to see how features in one part of the spectrum match up with those seen in other parts. It is like seeing with IR night-vision goggles, a regular camera, an ultraviolet camera, and X-ray vision, all at the same time.

The Pinwheel Galaxy is in the constellation of the Big Dipper. It is about 70 percent larger than our own Milky Way Galaxy about 21 million light years from Earth.

Image Credit: NASA

The Pinwheel Galaxy

It’s one of the last entries in Charles Messier’s famous catalog, but M101 is definitely not one of the least. The galaxy is big—roughly 170,000 light-years across, almost twice the size of our own Milky Way Galaxy. This multiwavelength view is a composite of images recorded by space-based telescopes. Color coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (x-rays, purple), the Galaxy Evolution Explorer (ultraviolet, blue), the Hubble Space Telescope (visible light, yellow), and the Spitzer Space Telescope (infrared, red). While the X-ray data shows the multimillion degree gas around M101’s exploded stars and neutron star and black hole binary star systems, the lower energy data shows the stars and dust that define M101’s grand spiral arms. Known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major. It’s about 25 million light-years away.

Image Credit: NASA