"the Pleiads, or watched the late-setting Bootes slowly fade, or the Great Bear"
The Big Dipper (or the Plough), part of The Great Bear (Ursa Major) constellation
Public DomainThe Big Dipper (or the Plough), part of The Great Bear (Ursa Major) constellation - Credit: Gh5046/Wikimedia Commons

These are all star constellations. Odysseus is using the position of the stars to help guide his path. Click here for more information on how to navigate using the stars.