NASA image of the Polaris system in 2006
Stella maris is the North Star, Polaris, alpha Ursae Minoris.It consists of three stars, a supergiant six times larger than Sun and two smaller companions.
Because it is near to the celestial north pole it shows approximately the direction towards north. Since Stella polaris does not appear to us to rotate on the sky like other stars during the night it has been of crucial importance to navigators especially at open seas, hence Stella maris, the Star of the Sea. It has also been called "steadfast star", "guiding star" and in German "Leitsterne".
"In traditional Indian astronomy, its name is Sanskrit dhruva tāra, literally "fixed star". Its name in medieval Islamic astronomy was variously reported as Mismar "needle, nail", al-kutb al-shamaliyy "the northern axle/spindle", al-kaukab al-shamaliyy "north star". (wikipedia)
Fixed, steady, guiding star - so a fitting symbol for Mary, Mother of Jesus who received it in 9th century liturgy. Another stellar epithet to this Jewish woman known as Stella maris in addition to Queen of Heaven and Stella manutis, the Morning Star.
"Our Lady, Star of the Sea is an ancient title for the Virgin Mary, mother of Jesus Christ. The words Star of the Sea are a translation of the Latin title Stella Maris, first reliably used with relation to the Virgin Mary in the ninth century.
The title was used to emphasize Mary's role as a sign of hope and as a guiding star for Christians, especially gentiles, whom the Old Testament Israelites metaphorically referred to as the sea, meaning anyone beyond the "coasts", or, that is to say, sociopolitical, and religious (Mosaic law), borders of Israelite territory.
Under this title, the Virgin Mary is believed to intercede as a guide and protector of those who travel or seek their livelihoods on the sea. This aspect of the Virgin has led to Our Lady, Star of the Sea, being named as patroness of the Catholic missions to seafarers, the Apostleship of the Sea, and to many coastal churches being named Stella Maris or Mary, Star of the Sea. This devotion towards Our Lady with this ancient title is very popular throughout the Catholic world." (wikipedia)
Ave Maris Stella
The beautiful celestial titles for Virgin Mary have inspired also some extraordinary music often heard during vespers in the evening.
We may well say that Monteverdi's Ave Maris Stella in his Vespro della Beata Vergine 1610 is literally heavenly!
Listen those amazing nine minutes in youTube