Spiral Galaxy M81
Messier 81 is a spiral galaxy about 12 million light-years away in the constellation Ursa Major. M81 is one of the most striking examples of a grand design spiral galaxy, with near perfect arms spiraling into the very center. Because of its proximity to Earth, its large size, and its active galactic nucleus Messier 81 is a popular galaxy to study in professional astronomy research. The galaxy's large size and relatively low apparent magnitude also make it a popular target for amateur astronomy observations.
Most of the emission at infrared wavelengths originates from interstellar dust.This interstellar dust is found primarily within the galaxy's spiral arms, and it has been shown to be associated with star formation regions.
The general explanation is that the hot, short-lived blue stars that are found within star formation regions are very effective at heating the dust and hence enhancing the infrared dust emission from these regions.
Source: en.wikipedia.org/wiki/Messier_81 - 29.09.2010
Spiral Galaxy M81
Here the spiral arms lead in an oval center, in contrast to our Galaxy System, which has a bar-shaped center and therefore is called Barred Spiral Galaxy.
