"Let us look at the elementary science of those days a little closer. How without Almanacs or Calendars could the day, or probable day, of the Sun's rebirth be fixed? Go out next Christmas Evening, and at midnight you will see the brightest of the fixed stars, Sirius, blazing in the southern sky--not however due south from you, but somewhat to the left of the Meridian line. Some three thousand years ago (owing to the Precession of the Equinoxes) that star at the winter solstice did not stand at midnight where you now see it, but almost exactly on the meridian line. The coming of Sirius therefore to the meridian at midnight became the sign and assurance of the Sun having reached the very lowest point of his course, and therefore of having arrived at the moment of his re-birth. Where then was the Sun at that moment? Obviously in the underworld beneath our feet. Whatever views the ancients may have had about the shape of the earth, it was evident to the mass of people that the Sungod, after illuminating the world during the day, plunged down in the West, and remained there during the hours of darkness in some cavern under the earth. Here he rested and after bathing in the great ocean renewed his garments before reappearing in the East next morning.
But in this long night of his greatest winter weakness, when all the world was hoping and praying for the renewal of his strength, it is evident that the new birth would come--if it came at all--at midnight. This then was the sacred hour when in the underworld (the Stable or the Cave or whatever it might be called) the child was born who was destined to be the Savior of men. At that moment Sirius stood on the southern meridian (and in more southern lands than ours this would be more nearly overhead); and that star--there is little doubt--is the Star in the East mentioned in the Gospels.
To the right, as the supposed observer looks at Sirius on the midnight of Christmas Eve, stands the magnificent
Orion, the mighty hunter. There are three stars in his belt which, as is well known, lie in a straight line pointing to Sirius. They are not so bright as Sirius, but they are sufficiently bright to attract attention. A long tradition gives them the name of the Three Kings. Dupuis says: "Orion a trois belles étoiles vers le milieu, qui sont de seconde grandeur et posées en ligne droite, l'une près de l'autre, le peuple les appelle les trois rois. On donne aux trois rois Magis les noms de Magalat, Galgalat, Saraim; et Athos, Satos, Paratoras. Les Catholiques les appellent Gaspard, Melchior, et Balthasar." (*) The last-mentioned group of names comes in the Catholic Calendar in connection with the feast of the Epiphany (6th January); and the name "Trois Rois" is commonly to-day given to these stars by the French and Swiss peasants.
Immediately after Midnight then, on the 25th December, the Beloved Son (or Sun-god) is born."

[ Carpenter, Edward: Pagan and Christian Creeds, DODO Press, p16-17 ]

(*) Translation: "Orion has three beautiful stars towards the environment, that are second magnitude and put upright online, the a near other, the people the calls the three kings. One gives to the three kings Pond the names of Magalat, Galgalat, Saraim; and Athos, Satos, Paratoras. The Catholics the call Gaspard, Melchior, and Balthasar."

[ Charles F. Dupuis : Origine de Tous les Cultes, Paris, 1822 ]