Purg. 30:1-12 Constellation

Quando il settentrïon del primo cielo,
che né occaso mai seppe né orto
né d'altra nebbia che di colpa velo,

e che faceva lì ciascuno accorto
di suo dover, come 'l più basso face
qual temon gira per venire a porto,

fermo s'affisse: la gente verace,
venuta prima tra 'l grifone ed esso,
al carro volse sé come a sua pace;

e un di loro, quasi da ciel messo,
'Veni, sponsa, de Libano' cantando
gridò tre volte, e tutti li altri appresso.

Dante begins with the settentrïon - the Little Dipper of the Northern sky, in which is found the North Star. For a relatively contemporary account of the heavens by a medieval astronomer, have a look at the Sphere of Sacrobosco:

It is to be noted that the pole which always is visible to us is called "septentrional," "arctic," or "boreal." "Septentrional" is from septentrio, that is, from Ursa Minor, which is derived from septem and trion, meaning "ox," because the seven stars in Ursa move slowly, since they are near the pole. Or those seven stars are called septentriones as if septem teriones, because they tread the parts about the pole.

The seven stars of the little dipper were also associated with the Hesperides, the daughters of Atlas who guarded the golden apples of Hera on a paradisal island at the western edge of the world. The apples were said to have been given to Hera as a wedding present by Gaia when the goddess accepted Zeus's hand in marriage.