The bright stars of Perseus can be seen above as a "J" with two strands of stars trailing off to the right. Algol is an eclipsing binary system, two stars orbiting one another with their orbital plane tilted such that one star passes in front of the other from our vantage. The system appears as a single star to us, even in the largest telescopes, but as one star eclipses the other, we see the total light from the system drop. Algol was one of the first such systems known and it is sufficiently bright with a large enough change in brightness that tracking its eclipses is an interesting project for the backyard astronomer. The stars around Mirfak, the brightest star in the constellation are part of open star cluster.

I have often thought that the asterism of Perseus resembles a tennis player tossing a ball in the air and raising a racquet to serve, the "J" representing the arms of the server and the strands to the right the legs. In the image below Perseus would appear to be serving into the back of partner Cassiopeia, seen as a "W"above Perseus. This image was acquired just before dawn in very early July, looking east from Valders Hall of Science on the Luther College campus. Note bright star Capella in Auriga sitting above a thin cloud bank and just popping out from behind the white siding of the astronomical observatory roof, following Perseus and Cassiopeia into the morning sky.