"In the time of King Herod, after Jesus was born in Bethlehem of Judea, wise men from the East came to Jerusalem, asking, "Where is the child who has been born king of the Jews? For we observed his star at its rising, and have come to pay him homage."
Think about it. They saw the same star in the heavens as the wise men. They saw it centered over Bethlehem. They had to know something significant was occurring in the stars. The Magi's story would have filled in important pieces of their own observations.
We don't know if it was fear of Herod that kept them from acting. That would have been a perfectly rational response. They knew everything Herod did to keep power, and would have been rightly afraid of his reaction.
Perhaps they were so wrapped up in their own power and position that they never even paid attention to the star. Perhaps even after hearing the story of the Magi, they no longer had any inclination to seek the Messiah. After all, God had been silent for 400 years, why would he show up to outsiders and not them?
To expect Him. And to seek Him out.