Gordon et al indicated in a study , they presented images that revealed:. These images show that M81 has a significant amount of cold dust associated with the spiral arms. From multiwavelength morphology comparisons, the dust heating is argued be dominated by recent star formation even at the longest MIPS wavelength. These results illustrates the need for additional theoretical and empirical work on how to accurately combine different SFR indicators, accounting for dust, age, and radiative transfer effects, to give an accurate view of the star formation in regions of galaxies.
But there are holes there… And not necessarily black ones! As Ioannis Bagetakos et al explained in a study :. A comparison with the holes found in two other spirals and two dwarf galaxies reveals that the ISM in M81 shares a lot of similarities with the two spirals, whereas the structure of its ISM is different to that in dwarf galaxies.
The two properties which most clearly illustrate this are the size distribution of the HI holes and their distribution in velocity. Our observations reinforce the idea that the amount of energy typically deposited in the ISM is the same, irrespective of galaxy type, but that the properties of HI holes depend on the characteristics of the host galaxy, notably the thickness of the neutral gas layer.
M81 is the first of the four deep space beauties discovered by Johann Elert Bode, who found it the pair on December 31, According to his historical notes:. The patch Alpha M81 appears mostly round and has a dense nucleus in the middle. The other, Beta, on the other hand, is very pale and of elongated shape. Only one supernova has been seen in Messier The supernova is named SN J. It was discovered on 28 March by F. Garcia in Spain. At the time, it was the second brightest supernova seen in the 20th century.
Messier 81 is the largest galaxy in the M81 Group. The M81 Group is a group of 34 galaxies in the constellation Ursa Major. Messier 81 and Messier 82 can both be easily seen using binoculars and small telescopes. An infrared image of Messier 81 taken by the Spitzer Space Telescope.
The galaxy is located approximately The angular size of M81 roughly corresponds to that of the full Moon. Messier 81 is tilted at an oblique angle when seen from Earth.
Its spiral arms consist of young hot stars, bluish in colour, that were formed within the last few million years. The spiral arms also contain a stellar population formed about million years ago.
The central bulge of M81 is home to significantly older stars, red in colour, and much larger than the central bulge of our own galaxy, the Milky Way. It has a strong gravitational effect on Messier 82 Cigar Galaxy and NGC , two other prominent members of the group. The close encounter between the galaxies occurred about million years ago. As a result, all three galaxies have had hydrogen gas stripped away.
The gravitational interaction has also resulted in the formation of filamentary structures in the group. The filaments are made of the gas that is being stripped away from the three galaxies. The interaction has also caused the gas to fall into the central regions of Messier 82 and NGC , resulting in increased star-forming activity. The galaxy is similar to our Milky Way, but our favorable view provides a better picture of the typical architecture of spiral galaxies.
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