Spiral Galaxies are definitely some of the most beautifully structured jewels of the Universe – galaxies with a grand design, showcasing elegant patterns of tightly bound bright spiral arms – so pretty! This particular galaxy – known as Messier Object 101 or more commonly as the Pinwheel Galaxy, is almost 70 percent larger than our Milky Way. It is ssso far that even light takes almost 21 million years to travel from this grand spiral to us!! And it is ssso big that it is estimated to contain more than 1,000,000,000,000 stars in it.
This image is a multi-wavelength view of the galaxy – combining datas from four instruments – Hubble Space Telescope (visible light), Spitzer Space Telescope (infra-red parts), Galaxy Evolution Explorer (Ultra-violet data) and Chandra Observatory (for the X-Ray image).
Doing multi-wavelength study of an astronomical object is very interesting. Each wavelength carries various informations about different regions of the object. The hottest areas – regions near black hole, colliding and exploding stars – are revealed in most details by the X-Rays (shown in purple here). The young and hot stars mostly emit in ultra-violet (blue areas of this picture). The dust lanes and the star-forming regions are best seen in infra-red (the red parts) while the visible wavelength range is mainly a result of the stars residing in the spiral arms (yellow parts).