(historical astronomy) Of or relating to the star Sirius, particularly in Egyptian or ancient Greek contexts.

plural of Sothic period

(astronomy) The roughly 1460-year cycle between successive alignments of the first days of the Egyptian civil calendar and the observational Sothic year.

plural of Sothic year

plural of Sothic cycle

(astronomy) The roughly 1460-year period of time between successive alignments of the first days of the Egyptian civil calendar and the observational Sothic year.

(astronomy) The span of time between successive heliacal risings of the star Sirius, equivalent to almost precisely 365¼ days.