AstroCrescent

2 Spiral galaxies in the constellation Ursa Major. Exposures 30 x 300 seconds. Darks x 20. Unity Gain 100 using ASIStudio. Autoguided. Messier 81 (on the left) and Messier 82 (on the right) are 2 superb spiral galaxies in the constellation Ursa Major. Messier 81 is a 6.9 magnitude object and is easily seen in 4/6 inch telescopes. It's coordinates are RA 09h 55.6m Dec +69° 04'. Messier 82 is a 8.4 magnitude object and is again easily seen in 4/6 inch telescopes. It's coordinates are RA 09h 55.8m Dec +69° 41'. Both of these galaxies are thought to be about 12 million light years away and separated by some 150,000 light years. These galaxies form part of the Messier 81 Galaxy Group. Both of them were discovered by Johann Elert Bode in 1774 and later added to the Messier catalogue in 1781. Messier 81 is a superb example of a spiral galaxy and has a diameter of at least 70,000 light years. In the central bulge of M81, much older, redder stars reside, while at the galaxy’s core lies a supermassive black hole about 70 million times the mass of our own Sun! Messier 82 is a great example of a cigar shaped galaxy and has a diameter of 35,000 light years and is a form of starburst galaxy. Gravitational interactions of M81 with M82 have stripped hydrogen gas away from both galaxies, forming gaseous filamentary structures in the group. These interactions have allowed interstellar gas to fall into the center of M82, leading to vigorous star formation or starburst activity. Note the slight haze between the galaxies. This is probably caused by the interaction of the galaxies on each other. However, in actual fact, this area of the sky is swathed with Integrated Flux Nebula. What the hell is that, you're thinking? Well, I will discuss this in my next blog, so look out for that. As regards imaging, these galaxies are easily seen with any camera and therefore can be imaged by beginner's and experienced alike. Go for it with a small refractor which will get both of them in the field of view or a larger telescope with a focal reducer. Late winter and of course Spring, are good times to get these 2 galaxies imaged and they are really easy to capture because of their brightness. Check them out soon. Get 2 or 3 hours on them and you will not be disappointed. See my blog at: https://www.astrocrescent.com/post/m81-m82