As an astronomer, I’m often asked whether conjunctions such as the one we just saw Monday evening in the western sky were what came to be described as the Christmas Star, or Star of Bethlehem as described by the three Magi astrologers in the Book of Matthew.
It’s true we don’t know the exact date of the birth of Christ despite our calendar’s insistance on a zero point on the timeline, and there are a number of morning planetary conjunctions we have calculated around that arbitrary, instantaneous mark – based on the objectively true orbital motions of the planets.
What we know: It must have been a morning apparition because it was said the star appeared in the east. While possible, I think a planetary conjunction ‘Star of Bethlehem’ is highly unlikely because the ancients were well aware planets ‘wandered’ against the backdrop of the ‘fixed stars’ and distinctly identified them.
More likely – if there actually was a rare brilliant light in the sky – is that a supernova suddenly burst forth in the morning sky, rising before the sun, shining brightly and appearing to move slowly westward across the morning sky day after day as Earth’s orbital motion demands. At the same time, given what we know about supernova and our ability to see their remnants and ‘run their clocks backwards’ – not to mention how they were recorded by ancient cultures around the world – we have no evidence for one around that time.
In the end, all we can really say is that we have no evidence for an astronomical source for the Christmas Star. To me, the conversation merely shows an intense human desire to see the natural world empirically confirm the perceived spiritual world’s sacred scriptures. It goes beyond simply waving a hand at something astonishing in nature and crediting it to our preferred god’s handiwork, and I can certainly appreciate the desire to know.
To me, it is more likely the author(s) and army of translators across the centuries simply interpreted the Book of Matthew’s original wording according to their individual level of understanding of astronomy and synthesized their words carefully for their target audience.
In truth, the topic can be a little problematic for astronomers since it involves a religious belief asking science – a system designed to interrogate and describe the natural world empirically – to confirm the historicity of something of apparent supernatural origin. Such a thing is by definition outside the scope of science…but we address it anyway, mainly because we love talking about the night sky.