Astronomical observations #24: Bode’s Galaxy (M81)

A distance of 11 million light years divides us from it! In its center there is probably a huge black hole with a mass of up to 70 million solar masses! The galaxy was discovered on December 31, 1774, by the German astronomer Johann Elert Bode. This is one of the most beautiful examples of symmetrical spiral galaxies. Here are tips on how to find and view this object. I invite you to read.

In the northern sky, about 10 degrees northeast of the Big Dipper, you can start your search. Under good, dark skies, 7 X 50 binoculars are enough to see an oval with a bright nucleus. We will probably see two galaxies close together, because the M81 is close to another known galaxy: M82, which I will describe in the next part. When we use a telescope with a minimum diameter of 6 inches (150 mm), we should be able to find the galaxy even in the suburban sky. It will not be the same view as in the village, but the bright nucleus of the galaxy should be shown. The object in the sky occupies an area of ​​23 X 13 arc minutes, i.e. close to half of the full moon in the sky. The brightness of the observed galaxy is +6.8 magnitude, so in ideal conditions, it would be possible to see this object with the naked eye through a person with great eyesight. When in good conditions we have a telescope with a diameter of over 8 inches (200 mm) and use a small magnification around 30 — 50X, we will see traces of two thin spiral arms that move away from the bright nucleus in opposite directions. Below is a simulation of the M81 view in a large telescope over 12 inches (300 mm). The better we have the conditions (darker sky), the more details of the spiral arms we will see. Watching the M81 outside the city, the object will probably seem small and not interesting, because then we will see only the core of the galaxy. Gentle arms under a bright sky just die in the light of city lights. M81 as in the picture below, I managed to see in the Polish mountains Bieszczady in 2013. I still remember this view to this day. In the deeply black sky, the galaxy was striking with its splendor. I recommend going to an astronomical rally and experience similar views without spending money on the equipment when you don't know if it's worth it.

Astronomers assume that our galaxy, the Milky Way, seen from outside, is very similar to the Bode’s Galaxy. The real dimensions of the M81 are around 84 X 46 thousand light years. The bright nucleus accumulates most of the more than 250 billion stars of the galaxy. The vastness of the cosmos is amazing, just think that many of these stars can have their planets, and that's just one of many millions of galaxies in the universe. On March 28, 1993, the Spanish amateur Francisco Garcia Diaz discovered the supernova SN 1993J in M81. When looking at the galaxy, he was lucky that suddenly a star appeared on her, which reached the brightness of +10.5 magnitude, which was visible in most amateur instruments.