I mentioned before that I think Horos is the star Sirius (Greek Σείριος "scorcher," referring to the "heat" it causes in midsummer; cf. Hesiod, Works and Days 585) and Anoubis is the star Canopus (Greek Κάνωβος—probably derived from Anoubis—the name of the pilot of Menelaus's (=Isis's) ship; cf. Conon, Fifty Stories VIII; Strabo, Geography XVII i §17).
I think I've identified a third star: Upuat (𓄋𓈐𓈐𓈐 "opener of ways") is Procyon (Greek Προκύων "before-dog"), the eighth-brightest star in the entire night sky. (You can see it in the star map I posted earlier: it is the bright star to the left of Orion and above-and-to-the-left of Sirius.) Apparently the name comes because it is seen to rise before Sirius, in the same way that Upuat "opens the way" for the rising soul, identified with Horos/Sirius, in the Pyramid Texts. It is also (along with Sirius) more northerly than Canopus (the three are more or less in a straight line), suggestive of the dogs that led Isis to Anoubis (which better fits Ploutarkhos's interpretation of the myth, though I think it's a later version).