The term 'DOG STAR' refers to the brightest star in the night sky, Sirius. Sirius is a binary star system composed of a white main sequence star and a faint white dwarf companion. The other crossword solutions are all famous dogs from popular culture. ASTA was a wire-haired terrier featured in the 1934 film 'The Thin Man'. LASSIE was a Rough Collie featured in the 1943 novel 'LASSIE Come Home' and subsequent films. BENJI was a mixed breed dog featured in the 1974 film 'BENJI'. Paddleboard is a type of surfboard used by dogs in the 2017 film 'A Dog's Purpose'. Rintintin was a Wire Fox Terrier featured in the 1922 silent film 'Foolish Wives'.