Previously, the most prominent explanation for the Star of Bethlehem was to identify one of many astronomical events in the sky as being the inspiration for the trip of the Magi. However, all the astronomical answers have detailed refutations, and general disproofs, so all the astronomical answers for the Star are dead.
In 1999, Michael Molnar put forth a completely new solution, where the Star originated as a report of a natal horoscope for 17 April 6 BC. This natal horoscope shows very impressive regal portents and points to Judea. It is very improbable that such a very rare planet configuration (averaging only once per millennium or longer) would coincide with the very restricted day of Jesus' birth (springtime in a year shortly before Herod's death in 4 BC), unless there is some causal connection. The Magi (as labeled by the gospel author) were astrologers, so they were only interested in horoscopes. The astrological solution is further supported by the presence of an astrological technical term ('in the east' meaning what astronomers call the 'heliacal rise') in the Nativity narrative of Matthew.
Importantly, Molnar has only identified the Star as originating from a particular natal horoscope, while making no statement about the nature or historicity of any of the other elements of the story in Matthew. So for example, the Magi might be astrologers as idealized by the Greeks of the time, or they might have been non-existent (invented by a latter-day Greek seeking omens for the birth of a great king), and they might have arrived on 17 April 6 BC or months later, and they might or might not have been three in numbers with given names. But for the Star of Bethlehem alone, Molnar's astrological solution is convincing.Bradley E. Schaefer, "Astronomical and Historical Evaluation of Molnar's Solution for the Star of Bethlehem" (Pre-Print December 19, 2016)