Since the XVII century, the most important goal of astronomers has been the study of the Milky Way – this giant collection of stars that Galileo saw through his telescope. The efforts of many generations of observer astronomers were aimed at finding out what is the total number of stars of the Milky Way, determining its actual shape and boundaries, and estimating its size. It was only in the 19th century that it was possible to understand that this is a single system that contains all the visible stars. On an equal footing with all, our Sun enters into this system, and with it the Earth and planets. Moreover, they are far from being located in its center, but on its outskirts.
It took many decades of careful observation and deep thought before the structure of the Galaxy was revealed to astronomers in its entirety. So they began to call the star system that we see – of course, from the inside – like a strip of the Milky Way. (The word “galaxy” is derived from the Greek “galacticos”, which means “milky.”)
It turned out that the Galaxy has a fairly regular structure and shape, despite the apparent raggedness of the Milky Continue reading