Originally posted by Symmetric Chaos
Probably a few weeks after his birth at minimum. It's just shown as a newborn in stories for simplicities sake. Matthew does explicitly state that the star "stopped over the place where the child was" so I'm not sure where you got the idea otherwise.
I believe he was more of a toddler age.
Actually, the Scriptures teach this:
"When Herod saw that he had been tricked by the wise men, he flew into a rage and ordered the execution of all the male children in Bethlehem and all its neighboring regions who were two years old and younger, according to the time that he had determined from the wise men." - Matthew 2:16
Christ was not an infant when the Magi came to visit (they knew it was time when they journeyed), he was nearer two years, a toddler.
Again, the Scriptures do not teach that the star of Bethlehem occured when Christ was born, rather when the Magi visited Him, around age two:
"After listening to the king, they set out, and the star they had seen in the east went ahead of them until it came and stopped over the place where the child was. When they saw the star, they were ecstatic with joy. After they went into the house and saw the child with his mother Mary, they fell down and worshiped him. Then they opened their treasure sacks and offered him gifts of gold, frankincense, and myrrh. Having been warned in a dream not to go back to Herod, they left for their own country by a different road." - Matthew 2:9-12
Also note that toddler Jesus was in the house, not the manger, as commonly depicted.