Star of Bethlehem X: Trying to Explain the Star

My apologies that this wrap-up piece has been delayed. I had intended to have it posted on January 1st, but the previous posting took longer to complete than I expected and, after that date, other commitments stopped me writing for a time.


After our walk through the evidence and through the different theories for explaining the Star of Bethlehem, we are left with three, fundamental questions to answer:

  • What was the Star of Bethlehem?
  • Will we ever know for certain that it did, or did not exist?
  • Can we ever identify the star in the sky (if it did exist)?

The first thing to say is that the Star of Bethlehem is that it is, in more senses than one, an article of faith. You either believe it existed, or you do not. You think that it was a miraculous event, or a perfectly normal event. And, if you support one particular theory over another, quite likely nothing is going to shake your faith that your theory is correct. People just agree to disagree. What I have done is to try to present the evidence, such as it exists, with all its ambiguities. I am not trying to sell a particular theory, but rather to present what we know or, in some cases, think that we know and let you make up your own mind. Of course, there is one particular theory that I favour because I think that it is the best fit to the evidence, but  there is an important health warning to put even on that theory.

  • Did the Star of Bethlehem exist?

This is a tricky one to answer. Experts are sharply divided. I have heard people defend strongly the line that “the majority of experts agree that the Star never existed” (theological side) and “the account is too detailed to be made up” (scientific side). And then, of course, there is the half-way house solution proposed a few years ago by Rod Jenkins that the Star did not exist in the sense that the Nativity story describes, but that Matthew added it based on real events that he had, himself, witnessed: that is, the visit of the Magi to Nero’s court and the 68 AD appearance of Comet Halley.

On the negative side, bear in mind that there has been a long and, at times, heated debate as to whether or not the Gospels show knowledge of the fall of the Temple in 70 AD, when the Romans defeated finally the Jewish revolt[1]: and this is a historical event that is well-dated and well-documented, yet ambiguously recorded in the Gospels! However, even if Luke seems to confuse his chronology quite badly at times, most of the people, places and events mentioned in the two versions of the Nativity story are known to have existed, which gives us some confidence that the events related were not just invented. Similarly, the fact that historical persons, places and events are recorded cannot be due simply to copying information from a history such as that of Josephus, as his book “The Antiquities of the Jews” was not published until 93 AD and his “The Wars of the Jews” was not completed until 79 AD, about the time that the Nativity story was set down.

For my part, I will go no further than to say, if the Star existed, the probable explanation is… I am not a biblical expert, nor a historian, nor an expert in ancient civilisations, so there are some elements of the story and its interpretation that I am not competent to judge. I have to defer to the opinions of the experts, although I am impressed by the way that the Star was so central to Christian beliefs from the earliest surviving records and depicted in so many early Nativity scenes that one does think that it must have been based on something real.

  • What was the Star of Bethlehem?

Back in my fifth post, I summarised the evidence this way:

While different writers have clearly added to and exaggerated the events, it is clear that:

  1. It appeared suddenly in the East.
  2. It was prominent, without ever being so spectacular that everyone saw it.
  3. It was visible for at least weeks or months.
  4. It had particular significance to the Magi who observed it.
  5. Weeks or, more likely, months passed between the Nativity and the arrival of the Magi.

It is easier to say what the Star of Bethlehem was not, rather than say definitively, what it was. However, beauty is in the eye of the beholder. It is a human tendency to ignore anything inconvenient and interpret the evidence in the most favourable way to support their ideas. Many people look at the (usually English) translation of a particular Greek word and give it huge significance, often falling into the trap that subtleties of meaning are usually lost in translation.

Occam’s Razor is usually a pretty good guide: the simpler a theory is to explain a set of events, the more likely it is to be true. The theories that depend on the exact interpretation of a particular word in a text that has been written and re-written over more than a thousand years and then translated (with all the pitfalls that translation implies), or that require the Star to have done all manner of things – appearing and disappearing at will and moving around the sky – are the most unlikely to be correct.

Similarly, explanations that involve very common phenomena such as Venus or a planetary conjunction are unlikely to be correct, unless the Magi shuttled back and forth across the desert dozens or hundreds of times before finding the “right” Star. The Magi knew the sky well and were attracted by something thoroughly unusual, but that does not mean outlandish. By process of using Occam’s razor it seems that all atmospheric phenomena (aurorae, ball lightning, meteor(s), etc.) must be ruled out. Standard planetary conjunctions are two-a-penny and fifteen-for-sixpence: they are so frequent that the camels of the Magi would have been worked to death crossing the desert forward and back several times each year. Similarly, supposing that two near-Earth Asteroids appeared – one to lead the Magi west to Jerusalem and a second, just at the right moment to lead them south from Jerusalem to Bethlehem – it would have been an incredible coincidence, especially as we know of just one case when a sufficiently large asteroid will pass sufficiently close to be visible with the naked eye and then, only briefly. Similarly, expecting the Magi to notice the almost imperceptible movement of a distant planet, just barely visible to the naked eye, is also pushing Occam’s Razor further than it will go willingly.

Similarly, there are many who wish to convince themselves that the Star of Bethlehem was a comet. This flies in the face of all logic given the terrible reputation of comets for bringing disaster[2]. Such beliefs are still present now, but were so much stronger two thousand years ago. However much people insist that the Chinese chronicles call the 5 BC star a “comet”, it was seen in a fixed position in the sky for two and a half months and that simply is not plausible behaviour for a bright comet.

Bright comets are of three kinds:

  • Objects that only get bright because they pass very close to the Sun (sungrazers).
  • Large comets that are visible for a considerable period of time.
  • Objects that pass very close to the Earth.

The 5 BC object was approximately 50 degrees from the Sun, which rules out a sungrazer, while an object passing very close to the Earth is generally only visible for short time[3] and will move a lot against the sky background while visible – it is very hard to imagine the Chinese giving a fixed position for it. Such objects are also brightest when opposite the Sun in the sky, not when relatively close to the Sun as the 5 BC object was. The only potential cometary fit is a large comet, probably moving away from perihelion, but this begs the major questions of why no movement was reported and why it was not seen earlier and closer to the Sun in the sky when, presumably, it would have been brighter. There are orbital solutions that would, just about, fit the visibility of the 5 BC object, but they are a real stretch.

Bright comets would have been a common sight to the Magi. In modern times the averages are a comet visible to the naked eye about every three years and one of negative magnitude about every ten years. What though is difficult to understand is how the Magi could have interpreted a comet as an auspicious event: comets generally provoked concern or terror, with predictions of catastrophe and the fact that the tail often looked like a sword was frequently taken as a augury of war. A bright comet would have been widely observed and, with King Herod close to death, taken as an omen[4].

All in all, it is hard to give any credit to the comet theory.

In contrast, the Triple Conjunction has an air of plausibility. Astrologically, it involved the planet associated with kings (Jupiter) and the planet that was the bringer of change (Saturn) coming together. That, in itself, has great significance. Over the years there has been a lot of debate about the astrological significance of Pisces – the constellation in which the triple conjunction occurred – to the Jews. Michael Molnar has argued convincingly that, in reality, it was Aries, the next zodiacal constellation after Pisces, that was associated with the Jews, in which the case for the triple conjunction is weakened.

On the negative side, suspicion is that the triple conjunction came a little too early to be convincing as an explanation for the Star. It was certainly very early compared to the Alexandrian date for the Nativity, as we see below, starting as much as two and a half years earlier.

Calendar_detailThere is also an objection that has been raised that there was a much more spectacular conjunction of Jupiter and Saturn, albeit a normal one, in 26 BC and an even more striking one in 86 BC when the difference in brightness between the two planets was much smaller than in 6 BC and the separation between the two planets was so small that they would almost have merged into a single star.

The event of August 11th 86 BC happened in Leo, very close to Regulus, the Royal star, and would have been observed low in the dawn sky, about twelve hours before the very closest approach of the two planets, which was 4 arcminutes.

The event of February 20th 66 BC, which happened in Pisces, very close to the Sun and that of October 6th 46 BC, which happened in Sagittarius, were similar to the 6 BC triple conjunction in that the separation of the planets was around one degree.

The event of June 29th 26 BC again happened very close to Regulus, would have happened in the evening sky in a relatively good position for observation and saw the two planets approach to 16 arcminutes, with a difference in brightness between Jupiter and Saturn more than a magnitude smaller than in 6 BC.

If the 6 BC event was so significant to the Magi, why not the 86 BC and 26 BC events that also involved Regulus, the Royal Star which, surely, was richer in astrological associations, given the Old Testament references to the coming of the Messiah as the “Lion of Judah” and the reference in the New Testament Book of Revelations to Jesus as the “Lion of Judah”? And if two, or even three objects were involved, why does Matthew speak of “φαινομένου ἀστέρος“ – “of the appearing star” with its strong implication of a single object that appeared suddenly? Conjunctions happen slowly over a period of days, or even weeks and the 7 BC Triple Conjunction lasted over six months: there was nothing sudden about it.

Triple conjunctions can happen between any two superior planets – those outside the orbit of Earth. The more distant the planet, the larger the fraction of triple conjunctions relative to normal ones. We have already seen that conjunctions of Venus and Jupiter can be incredibly spectacular: can Venus and Jupiter produce triple conjunctions that might also be extremely significant to the Magi?

Technically, the answer is “no”, because Venus is not a Superior planet. In practice though, sequences of conjunctions of Venus and Jupiter can happen. The 3 BC and 2 BC conjunctions of Venus and Jupiter in Leo were part of a remarkable sequence in which FIVE conjunctions between the two planets happened in thirty-three months, the third-shortest interval in the last five centuries BC.

Conclusion: you can always find some kind of special configuration of conjunctions… if you look hard enough.

Similarly, it is hard to be very moved by an invisible occultation of Jupiter by the Moon, even if it appeared in Aries and – possibly – was depicted in the Antioch coin. However, before we get excited about the Antioch coin, struck in the Roman province of Syria nearly 20 years after the Nativity, we should remember that the motive of a zodiacal symbol, a crescent moon and a star was present in many Roman coins of the 2nd and 3rd Centuries AD. The coinage of Hadrian, Comodus, Caracalla and many other emperors from these centuries was full of this astrological symbology. A very similar coin to the supposed occultation of Jupiter dates from the time of Nero in which we see a crescent Moon and a star made with seven dots, symbolising the seven known celestial bodies – the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn.

If we take a look at the catalogue of 626 Roman coins from Antioch ( we will find no fewer than fifty-eight (almost 10%) show a ram, of which thirty-one also show a star, or a crescent Moon, or both. The Ram with a star and/or crescent Moon was particularly common in coinage from the middle of the 3rd Century AD, but present over almost three centuries of coinage from Roman Syria.

BMC_065The so-called Antioch Coin, issued in Antioch (Syria) in 12-13 AD, just before the death of Augustus. The “head” shows the head of Zeus. The tail shows a leaping ram looking over its shoulder at a brilliant star, with the legend “ΕΠΙ ΣΙΛΑΝΟΥ ΑΝΤΙΟΧΕΟΝ” (Epi Silanoi Antiocheon – Silanus, Legate of Antioch).

RPC_4290A coin with a motive almost identical to the Antioch Coin, issued in Antioch (Syria) in under Nero, between 54 and 68 AD. The “head” shows a bust of Tyche. The tail shows a leaping ram looking over its shoulder at a brilliant star, with the legend “ΕΠΙ ΚΟΥΑΔΡΑΤΟΥ” (EPI KOYADRATOY, Quadratus, Magistrate). The star is represented as seven points. This was a highly significant number in Roman astrology as it represented the seven celestial bodies: the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn.

What about occultations of Jupiter by the Moon? Are they rare?

No! Quite the contrary. Between January 1st 20 BC and December 31st 100 AD there were 256: an average of two per year. Of these 34 were visible from the Middle East: about one every four years. And 99 of the 256 occultations, practically one each year, involved a crescent Moon less than 30% illuminated.

So, in summary, we are talking about a phenomenon that the Magi would not have seen because it occurred so low in the sky at sunset, that was so common that it repeated almost every year, often in much more observable circumstances and that may have been represented on a coin but, if so, appeared on almost 10% of known coins struck over three centuries in Syria.

The standard answer to the criticism that the March and April 6 BC occultations would not have been visible to the Magi is “ah yes, but they would have known about them” (i.e. they would have calculated that an occultation had occurred), which rather suggests that they would have known about all the others too: statistically, about one occultation of Jupiter by the Moon would have taken place in Aries every six years. Only the fact that the invisible occultation happened at about the right time makes it an attractive explanation for the Star of Bethlehem: in just about everything else, Occam’s Razor shreds it.

What about the 5 BC Chinese star? For me it is the most convincing object for multiple reasons:

  1. It appeared at the right time, almost exactly a year before Herod’s death.
  2. It would have appeared suddenly, which is the Greek word that Matthew uses.
  3. It would have appeared in the east in the pre-dawn sky.
  4. Over a period of two to three months it would be in the south at the same time of day.
  5. It was visible for a considerable period of time, with the implication that it must have been very bright, but the Chinese would most likely have lost sight of it as it faded with the arrival of the monsoon rains.

Table 3.1 of the Clark and Stephenson book, “The Historical Supernovae” lists seventy-five candidate novae and supernovae of the pre-telescopic era. They class the reliability of classification of the 5 BC object as a nova as “2” on a 5-point scale from 1 to 5: in other words, not a certain nova, but very probable; one of just twenty objects that were of long duration and high reliability, nine of which are now known to have been supernovae and the only one in BC dates. That is definitely distinguished company for the 5 BC object to keep.

An argument used against this object is that it is in the wrong position to be a Galactic nova. In fact, the original position given by Clark and Stephenson gives a Galactic Latitude of -25°, actually close to the median distance from the Galactic Plane for bright Chinese novae and supernovae and consistent with a bright nova that is relatively close to the Sun. The revised position (which is slightly to the upper left of the position that I show in the star map below), taking into account the Korean observations, actually shifts the nova rather closer to the Galactic Plane.

Nova Aql 5The biggest single objection though to the nova is another one. The stars of 61, 64 and 70 AD were also long-duration, likely novae. Why was one of these not the star of the Magi? The only answer is “they were seen at the wrong time”, but we know that the Chinese and the Magi would have observed at least a few bright novae every century. Why did the Magi not arrive a century too early? Or two centuries?

In other words, if the Star of Bethlehem was a STAR, the 5 BC object ticks all the boxes for time, place and visibility. However, just as the 7 BC triple conjunction is plausible as a candidate Star only because it was seen around the right time, because there was really not so much to call attention to it above other, far more spectacular conjunctions, even a bright nova in 5 BC would have been “just another bright nova” to the Magi.

What then made the 5 BC star the Star of the Magi?

Over the years I have become increasingly convinced that no single event could be the sign that the Magi were searching for.

Perhaps it was the last great astronomer-astrologer, Johannes Kepler, who got it right. Kepler pointed out the remarkable similarity of the astrologically extremely significant conjunction of Jupiter and Saturn, followed by a similarly significant configuration of Jupiter, Saturn and Mars and then by a bright nova (the term “supernova” would not be coined for more than three hundred years) to events around the time of the Nativity. He speculated that the conjunction of Jupiter and Saturn and later grouping of Mars, Jupiter and Saturn might have been followed one to two years later by a nova that would be the Star of Bethlehem. Of course, Kepler did not know of the Chinese observations of the object in 5 BC. Had he done so, it would have been his Eureka moment.

It seems unlikely that any single event was the trigger for the Magi. All the ones that have been suggested are either events that are too common to have called the attention of the Magi, or too implausible. The Magi would have seen a combination of signs in the sky that led them to seek the Messiah. Most likely, those signs started with the triple conjunction, with each new sign in the sky telling the Magi that great events were forthcoming, but the Magi needed the final sign: the new star blazing in the sky, to know that the event was that a new King had been born.

If you want a Star of Bethlehem, it was, most probably, the 5 BC star, but of itself, it was far from being the whole story.



This brings us to the end of our journey. Whatever your views on the Star of Bethlehem, I doubt very much that I have changed them, but I hope that I have made you think about the evidence and how it is obtained. I also want to make people realise that we should question some of the statements about the Star made blindly by people who have never checked the evidence for themselves.

The search for the Star of Bethlehem is a fascinating journey through many fields of science and culture. It is the greatest mystery and, all in all, it would be just a little sad if we ever were able to resolve it beyond all doubt but, with modern knowledge and modern techniques, we are probably as close to resolving the mystery as we ever will be.

[1] This is one of the so-called contextual clues used to date the Gospels. Those who believe that the Gospels show no knowledge of the destruction of the Temple put an early date on the Gospels – some experts dated the first as having been written as 50 AD – while those who argue that the Gospels do refer to the destruction of the Temple have given much later dates, with some experts even having argued that Luke was written in the early 2nd Century AD. That said, as even the oldest surviving fragments of the Gospels date from the 3rd Century AD, we have no idea what changes or modifications may have happened between the original writing and the final compilation of the definitive text of the New Testament.

[2] Some of the modern tales may be apocryphal, but there is no doubt that Comet Delavan of 1914 was taken by many in Europe as a sign of the imminent outbreak of war. The pass of the Earth through the tail of Comet Halley in 1910 caused widespread unease, bordering on panic. The appearance of Comet Bennett in 1970 was said to be interpreted by Arab soldiers as being a secret Israeli war weapon. Comet Hale-Bopp caused a massed suicide of the Heaven’s Gate Cult in 1997 and the close pass of Comet Elenin in 2010 led to much internet speculation about the end of the world. All these cases of comet hysteria have happened in the last century or so of modern, enlightened times.


[3] An exception is Comet Wirtanen, a faint, periodic comet that will pass close to the Earth at the end of 2018. It will remain bright enough to see with the naked-eye for perhaps as much as three months because its orbit will run almost parallel to the Earth’s at that time, tracking the Earth over this period. However, in that time it will cross almost the entire sky: no one could possibly give a fixed position for it!

[4] King Herod was very much influenced by the Roman world in which comets foretold the deaths of rulers and the fall of kingdoms. No Magus in his right mind would have gone to Herod with news of a bright comet in 5 BC and, with the precarious state of health of Herod at that time well known, the appearance and meaning of a bright comet would have been widely commented and understood, particularly by writers such as Josephus who chided the Jews for ignoring the warning of Comet Halley in 66 AD.

2 thoughts on “Star of Bethlehem X: Trying to Explain the Star

  1. Dear Mark R. Kidger,
    In your post you quite rightly note: “Occam’s Razor is usually a pretty good guide: the simpler a theory is to explain a set of events, the more likely it is to be true”.
    Here is a very simple scientific explanation for Bethlehem star observations, Herod’s behaviour etc. with several possibilities to verify it.
    According to the Gospel the Magi from the east came to Jerusalem, saying, “Where is he who has been born king of the Jews? For we saw his star when it rose…”
    It is extremely important to note: the Magi do not say they saw the “star” in their country, as it has been mistranslated and misinterpreted since antiquity, but “when it rose”. Furthermore, the Magi speak about only one sighting of the rising star, and this means they were probably near Jerusalem! They came to Jerusalem in the late morning or afternoon, so the “star” was not visible in daylight and no one could see it.
    For further details, see my site “On possible historical origins of the Nativity legends” .
    Alexander Reznikov, Moscow.


    1. Dear Alexandre

      First, my apologies for the delayed response. Your comment is a very interesting one. There is a body of opinion that believes that the Magi who met King Herod were not the ones who had seen the Star originally but, instead, were sent as messengers and so could have been in Jerusalem when they, themselves, first saw the Star.

      There are various translations of the phrase used by Matthew “τὸν ἀστέρα ἐν τῇ ἀνατολῇ (ton astera en té anatolé)”. The popular, modern translation is “at its rising” or, “in the first light of dawn”, implying first visibility after solar conjunction. My Greek astronomer colleague says that the phrase just means “in the east” and that there is no significance other than that to the fact that the Greek word used is in plural. I have asked her about the suggestion that the use of the plural has a special significance and she has told me that if the intention is to say “in the east” (i.e. that the Star was rising), this is the correct Greek grammar. Of course, earlier, we have the comment “we have seen his star in the east” which, in that context, she tells me, is stating that the observers were in the east!

      So, in summary, the text appears to say that the Star was first seen by observers in a country to the east of Jerusalem and was in the eastern sky – that is, rising. However, it is quite possible that the Magi who met Herod were not the original observers.

      Of course, the biggest problem of all is that the version of Matthew’s text that we have is a copy of a copy of a copy and we do *not* know if these were his exact original words or, in contrast, there have been subtle (or not so subtle) alterations since.


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