Astronomical Observations #27: Pinwheel Galaxy (M101)

When we have the opportunity to look at the M101 through a telescope, this picture will probably remain in our memory for a long time. Above, we see a photograph M101 made with a long exposure time, It shows a beautiful, colorful galaxy facing perpendicular to us. It lies 21 million light years from Earth. To find this object with angular dimensions 24' to 23' (occupies in the sky an area not much smaller than the full moon) and brightness + 8 magnitudes, we need dark sky and binoculars 7 X 50. Unfortunately, due to the large angular dimensions in the sky, brightness the surface of this galaxy is quite low, so in such binoculars it will be only a brighter spot than the sky background. M101 find in the sky about 5.5° above the last star of the Big Dipper (star Alkaid). To be able to say that the object being viewed is a spiral galaxy, we need a telescope with a minimum diameter of 8 inches (200 mm). However, being in the Bieszczady Mountains in Poland in 2013, a 12-inch (300 mm) telescope showed me a view somewhat similar to the one we see in the photo below. A small, bright core and clear traces of the M101 spiral arms were evident. An unrecognizable view with flickering stars in the background. Seeing a galaxy that is more than 20 million light-years away is a real journey through time. This is one of the oldest lights that have reached my eye.

The Pinwheel Galaxy is therefore one of the obligatory positions of every amateur astronomer. Unfortunately, due to the worse quality of the sky in the world, searching for it in suburban areas is a real challenge. Light pollution causes that the sky lovers have to travel longer and longer distances in search of the dark sky. Let's hope that the best areas of the truly dark sky we have left will be protected from the development of artificial lighting. 20 years ago, even in the center of Europe there were many places where the night sky was unpolluted by urban light. Today, amateur astronomy isn't very popular because people are seeing less and less the real night sky full of stars along with the Milky Way, which is completely invisible in cities.