Christmas Star shines in a cosmic ballet

Heather Couper and Nigel Henbest wonder what celestial sight heralded the birth of Jesus

What was the Star of Bethlehem? "... when Jesus was born in Bethlehem of Judea in the days of Herod the King, behold, there came wise men from the east to Jerusalem, saying, where is he that is born King of the Jews? For we have seen his star in the east, and are come to worship him" (Matthew 11, 1-2).

With the brilliant planet Venus now starting to put on a dazzling display in the western sky, it is an appropriate time to ask what the Christmas Star might have been.

Astronomy may be able to come up with an answer, but only if we can pinpoint the likely date of Christ's birth. Confusingly, it was not in the year zero (which didn't exist, as 1 BC led straight to AD 1), and probably took place several years earlier. The contradiction arises in the calculations of a sixth-century monk called Dionysius Exiguus, who attempted to draw up a calendar by adding together the lengths of the reigns of all the Roman Emperors. But alas, he managed to forget the four-year reign of Octavian - consigning Jesus to a birth some time BC!

We can date Christ's birth to the reign of Herod, who we know from biblical sources died shortly after an eclipse of the Moon. There were eclipses in 4, 5 and 7 BC.

What riveting sky-sights were there on show a few years BC that might have been the Christmas Star? We can eliminate one suspect immediately: Halley's Comet. Although the Italian Renaissance painter Giotto di Bondone executed a beautiful nativity scene with the comet (which he had seen in 1301) as his "star", it was never thus. Halley's Comet, which enters the inner Solar System every 76 years, made a close pass to Earth in 12 BC - but that's just too early.

Chinese astronomers observed a "broom-star" - possibly a comet with a tail - for 70 days in 5 BC. Strangely, they reported no movement of their broom-star, which is unusual for a comet. Some astronomers believe that the Chinese instead saw a nova - a faint star that dramatically flares up when a companion star dumps material on it.

Whether a comet or a nova, whatever appeared in 5 BC would have been a striking sight in the sky. So why did no one in the west mention it? In particular, why was Herod so surprised when the "wise men" came to his palace claiming to have seen Christ's star in the east?

The answer may lie in the nature of the wise men themselves. They were probably not kings, but astrologers hailing from Babylon. And, like astrologers today, they would not have been interested in sudden, unexpected happenings in the sky, but in the predictable movements of the Moon and planets and the "aspects" they make with each other. So the "star" may have been a much more subtle affair, apparent only to astrologers.

Two unusual groupings of planets took place around the time of Christ's birth. In 7 BC, Jupiter and Saturn indulged in a cosmic ballet that they put on only once every 139 years. That year, in the constellation of Pisces, they appeared to come together and draw apart again on three separate occasions. This "triple conjunction"spoke volumes to the astrologers. In their interpretation, Jupiter was the king of the gods, Saturn stood both for justice and the land of Palestine, while Pisces represented the Jewish people. The sky was saying that a Jewish Messiah would soon be born.

In 2 BC an even more spectacular conjunction took place. On 17 June, "godly" Jupiter almost appeared to merge with "female" Venus in the constellation of Leo - another star pattern associated with the Jews. Stunning though the conjunction must have been, it was probably not the Christmas Star - for Herod would have been dead by then.

What's Up

The heavens are taking on a decidedly more wintry look now with the appearance of Orion in the east. From now until March, the mighty hunter - along with his adversary Taurus and two faithful dogs - will occupy centre-stage in the night sky.

Just to the east of the Orion tableau is the constellation of Gemini. Around the night of 14 December, look to the skies to see many more bright shooting stars than usual (up to 90 an hour), apparently emanating from Gemini's direction. This is an effect of perspective: the Geminid meteors actually come from a nearby expired comet that rejoices in the name of Phaethon.

Staying in the Solar System, look west to spot the elusive planet Mercury. At the end of the month, it is setting more than an hour after the Sun. Mars, too, is visible in the evening twilight. And Saturn is still on view in the evening sky, as a steadily shining, brightish "star" below the barren Square of Pegasus.

But the bright new arrival on the scene is Venus, settling in for a six- month residency as the Evening Star. On Christmas Eve the thin crescent Moon will be about 14 moonwidths to the north - making a pretty photo- opportunity if you're not partying.

December Diary (all times GMT)

7 1.27am full moon

14 10am Maximum of Geminids meteor shower

15 5.32am Moon at last quarter

22 2.23am New moon

22 8.17am Winter Solstice

28 7.06pm Moon at first quarter

BBC Radio 4 is broadcasting a two-part series 'Modern Magi' with Heather Couper, the Bishop of Monmouth and Paul Vallely, also of the 'Independent', on a 20th century journey to Bethlehem, at 11am on Saturdays 23 and 30 December.

Suggested Topics
Arts and Entertainment
Gregg Wallace in Summer's Supermarket Secrets
tv All of this year's 15 contestants have now been named
The giant banner displayed by Legia Warsaw supporters last night
football Polish side was ejected from Champions League
Arts and Entertainment
Could we see Iain back in the Bake Off tent next week?
tv Contestant teased Newsnight viewers on potential reappearance
Life and Style
A picture taken on January 12, 2011 shows sex shops at the Paris district of Pigalle.
i100(and it's got nothing to do with the Great British Bake Off)
Angelina Jolie with her father Jon Voight
peopleAsked whether he was upset not to be invited, he responded by saying he was busy with the Emmy Awards
Bill Kerr has died aged 92
peopleBill Kerr appeared in Hancock’s Half Hour and later worked alongside Spike Milligan and Peter Sellers
news It's not just the world that's a mess at the moment...
footballPremiership preview: All the talking points ahead of this weekend's matches
Keira Knightley poses topless for a special September The Photographer's issue of Interview Magazine, out now
ebooksAn evocation of the conflict through the eyes of those who lived through it
The Ukip leader has consistently refused to be drawn on where he would mount an attempt to secure a parliamentary seat
voicesNigel Farage: Those who predicted we would lose momentum heading into the 2015 election are going to have to think again
Arts and Entertainment
Cara Delevingne made her acting debut in Anna Karenina in 2012
film Cara Delevingne 'in talks' to star in Zoolander sequel
Mario Balotelli pictured in his Liverpool shirt for the first time
Life and Style
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

C# Algo-Developer (BDD/TDD, ASP.NET, JavaScript, RX)

£45000 - £69999 per annum + Benefits + Bonus: Harrington Starr: C# Algo-Develo...

Senior Data Scientist (Data Mining, Apache Mahout, Python,R,AI)

£60000 - £70000 per annum + Benefits + Bonus: Harrington Starr: Senior Data Sc...

Data Scientist (SQL,Data mining, data modelling, PHD, AI)

£50000 - £80000 per annum + benefits+bonus+package: Harrington Starr: Data Sci...

Java Developer - 1 year contract

£350 - £400 Per Day: Clearwater People Solutions Ltd: Our client based in Cent...

Day In a Page

Ukraine crisis: The phoney war is over as Russian troops and armour pour across the border

The phoney war is over

Russian troops and armour pour into Ukraine
Potatoes could be off the menu as crop pests threaten UK

Potatoes could be off the menu as crop pests threaten UK

The world’s entire food system is under attack - and Britain is most at risk, according to a new study
Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

Seoul's plastic surgery industry is booming thanks to the popularity of the K-Pop look
From Mozart to Orson Welles: Creative geniuses who peaked too soon

Creative geniuses who peaked too soon

After the death of Sandy Wilson, 90, who wrote his only hit musical in his twenties, John Walsh wonders what it's like to peak too soon and go on to live a life more ordinary
Caught in the crossfire of a cyber Cold War

Caught in the crossfire of a cyber Cold War

Fears are mounting that Vladimir Putin has instructed hackers to target banks like JP Morgan
Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years

Salomé: A head for seduction

Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years. Now audiences can meet the Biblical femme fatale in two new stage and screen projects
From Bram Stoker to Stanley Kubrick, the British Library's latest exhibition celebrates all things Gothic

British Library celebrates all things Gothic

Forthcoming exhibition Terror and Wonder: The Gothic Imagination will be the UK's largest ever celebration of Gothic literature
The Hard Rock Café's owners are embroiled in a bitter legal dispute - but is the restaurant chain worth fighting for?

Is the Hard Rock Café worth fighting for?

The restaurant chain's owners are currently embroiled in a bitter legal dispute
Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival

In search of Caribbean soul food

Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival
11 best face powders

11 best face powders

Sweep away shiny skin with our pick of the best pressed and loose powder bases
England vs Norway: Roy Hodgson's hands tied by exploding top flight

Roy Hodgson's hands tied by exploding top flight

Lack of Englishmen at leading Premier League clubs leaves manager hamstrung
Angel Di Maria and Cristiano Ronaldo: A tale of two Manchester United No 7s

Di Maria and Ronaldo: A tale of two Manchester United No 7s

They both inherited the iconic shirt at Old Trafford, but the £59.7m new boy is joining a club in a very different state
Israel-Gaza conflict: No victory for Israel despite weeks of death and devastation

Robert Fisk: No victory for Israel despite weeks of devastation

Palestinians have won: they are still in Gaza, and Hamas is still there
Mary Beard writes character reference for Twitter troll who called her a 'slut'

Unlikely friends: Mary Beard and the troll who called her a ‘filthy old slut’

The Cambridge University classicist even wrote the student a character reference
America’s new apartheid: Prosperous white districts are choosing to break away from black cities and go it alone

America’s new apartheid

Prosperous white districts are choosing to break away from black cities and go it alone