What is "canicula"

Dog Star \Dog" Star`\ Sirius, a star of the constellation Canis Major, or the Greater Dog, and the brightest star in the heavens; -- called also Canicula, and, in astronomical charts, [alpha] Canis Majoris. See Dog days.

Canicula \Ca*nic"u*la\, n. [L. canicula, lit., a little dog, a diminutive of canis dog; cf. F. canicule.] (Astron.) The Dog Star; Sirius.