Aristaeus' presence in Ceos, attested in the fourth and third centuries BC, was attributed to a Delphic prophecy that counselled Aristaeus to sail to Ceos, where he would be greatly honored. He found the islanders suffering from sickness under the stifling and baneful effects of the Dog-Star Sirius at its first appearance before the sun's rising, in early July. In the foundation legend of a specifically Cean weather-magic ritual, Aristaeus was credited with the double sacrifice that countered the deadly effects of the Dog-Star, a sacrifice at dawn to Zeus Ikmaios, "Rain-making Zeus" at a mountaintop altar, following a pre-dawn chthonic sacrifice to Sirius, the Dog-Star, at its first annual appearance, which brought the annual relief of the cooling Etesian winds.