Earlier work has argued that the time for the consultation of Apollo’s oracle in

13  Delphi was signalled by the heliacal rising of the constellation of Delphinus.1 This

14  paper tests this idea in three ways: firstly, by applying it to the timing of known

15  rituals and sacrifices that took place outside Delphi in preparation for the de-

16  parture of processions sent to Delphi for the annual oracular consultation;

17  secondly, the paper investigates the foundation myth and landscape of the

18  sanctuary of Apollo in Delos in association with the timing of the major cult rites,

19  as well as the landscape of the Cretan sanctuary of Apollo in Dreros. The aim is to

20  investigate whether the landscape and positioning of the key structures in these

21  sanctuaries can be associated with specific astronomical observations of Del-

22  phinus, which could have signalled the arrival of key moments in the year of

23  religious significance in the sanctuaries in question. Finally, the timing of major

24  festivals held in Delphi, Athens, Delos and Dreros is plotted against the timing of

25  the major phases of Delphinus in order to infer whether these cult rites can be

26  associated with the movement of the constellation.