Cepheus

 This image shows what the author has always imagined as the "house" asterism of Cepheus lying on its side, Errai marking the pointed roof of the house, with Alfirk and Alderamin outlining a wall of the house. The other wall is formed by the two bright stars nearly straight below Alfirk and Alderamin. Alfirk, also known as Beta Cephei, is the prototype of a class of pulsating stars, hot B-class stars that pulsate with periods of a few hours and brightness variations of several percent. Delta Cephei is the prototype of the famous Cepheid pulsating variable stars. The relationship between period and luminosity makes them important for determining distance in the universe.