While the Dipper may rule the sky of spring and early summer, different stars and new opportunities await the sky's watchers in late summer and fall.

High in the western sky is the “Summer Triangle” of Vega, Deneb, and Altair, leading their respective constellations of Lyra the Harp, Cygnus the Swan, and Aquila the Eagle. To the east of the Triangle flies the square of Pegasus, the winged horse. I have never thought this asterism looks much like a horse, let alone the kind that flies, but its four bright stars do resemble a baseball diamond. You can easily spot home plate and the bases, while the Milky Way to the north represents the fans in the stadium. A little further to the east is Andromeda the Princess, and Perseus.

We now focus on Beta Persei. In 1603, Johann Bayer published a star atlas in which stars in the different constellations were given Greek letters in approximate order of brightness. Many stars are numbered instead, according to John Flamsteed's 1725 catalog, which used increasing numbers from west to east in each constellation.

Beta Persei, the demon star of mythology, is more commonly known as Algol, the star that winks! Every 2.9 days, or 69 hours, Algol drops in brightness by a full magnitude for about ten hours. It is one of the finest examples of a celestial event: a star that is not just there, but is visibly doing something for all to see.