Arcturus which is the brightest star of summer, and the brightest star of the constellation Bootes, the Herdsman. It is a fascinating star and compared to our Sun is somewhat mind boggling. Indeed, it is about 115 times as luminous as our Sun. And if we could place our Sun side by side next to Arcturus, it would look like a dwarf because although our Sun is almost a million miles wide, it would take 20 of our Suns lined up end to end to equal the diameter of Arcturus. Or, if you'd like to think of it in really mind boggling terms, since it would take 108 of our Earths lined up end to end to stretch across the middle of our Sun, it would take over 2,000 Earths to stretch across Arcturus' middle. Wow!