The astronomy of Christmas is chiefly centered around verifiable celestial events that occurred at or near the time of birth of Jesus. Astromers have expended considerable research on reconstructing movements of planets, stars and comets that could best explain Biblical accounts of the era.
The Christian New Testament Gospel of Matthew, includes description of three "Maji" from the east who follow the Star of Bethlehem to the location where they find Jesus shortly after his birth. For example, the Gospel of Matthew, Chapter 2, verse 1 of the New International Version of the Bible gives:
After Jesus was born in Bethlehem in Judea, during the time of King Herod, Magi from the east came to Jerusalem and asked, “Where is the one who has been born king of the Jews? We saw his star when it rose and have come to worship him."
Movements of celestial bodies in this era have been examined, in order to determine which astromonical events most closely mirrors the Biblical and historical records.
The relevance of these modern studies is strengthened by the belief that the "Maji" referred to would likely have been ancient astronomers, paying close attention to celestial events for many reasons.
Star of Bethlehem
Adoration of the Maji by Florentine artist Giotto di Bondone (1267–1337)
Early research focussed on what the most likely type of astronomical events would have comprised the sighting ot the Christmas Star.
The Star of Bethlehem is also linked to Old Testament prophecies. For example, the Book of Numbers, Chapter 24, Verse 17 of the New International Version of the Bible gives:
I see him, but not now; I behold him, but not near. A star will come out of Jacob; a scepter will rise out of Israel. He will crush the foreheads of Moab, the skulls of all the sons of Sheth.
The concept that a nova, or exploding star, was the Star of Bethlehem can be ruled out, because the Chinese, who kept extensive and detailed astronomical records of nova events spanning this ancient era, records no nova events whatsoever in this entire time frame.
The notion that the Star of Bethlehem was a comet seems not to be tenable, since comets portended adverse events for ancient astronomers of this region. Certainly, as Mosley observes, the Maji who followed the star would not have followed a comet, in the hope of witnessing the arrival of the foretold event of the birth of the Prince of Peace.
A conjunction of planets is the most likely explanation for the Star of Bethlehem. Johannes Keppler in the year 1614 was the first to elaborate on the planetary conjunction theory of the Star of Bethlehem.
Conjunction of Jupiter and Saturn
Firstly, it is important to note that there was no apparent linguistic distinction in the ancient world between stars and planets. The level of knowledge required to distinguish these two types of celestial bodies was not broadly developed throughout the ancient world. Ptolemy did not appear to work out the fundamentals of planetary motion until over a century later.
Astronomers have determined that Jupiter (considered by ancient astronomers as the king of the skies) and Venus (viewed as the queen of the skies); brightest object save sun and moon, had a close conjunction as viewed from the lands of ancient Israel somewhat prior to sunrise on August 12 in the year three BC.
This conjunction of August 12, in 3 BC, occurred in the constellation of Leo, with which Judea was associated in the ancient astronomer's lexicon.
Ramirez observes that the Leo constellation contains Regulus, known to the ancients as the king star.
Approximately one year later, on June 17, in 2 BC, the conjunction recurred.
Moreover, thrice between these two conjunctions Jupiter was almost tangent to Regulus.
It is not clear which set of conjunctions would have most attracted the attention of contemporary observers --possibly the entire sequence of repeated conjunctions.
Role of Herod
King Herod "the Great" was the local governor of this Roman Province, in which the Biblical events were unfolding. The role of Herod is further clouded by the possibility that Herod's own death, according to some historical analysts, may have occurred as early at 4 BC. In 1896 Emil Schürer, followed by many scholars, first established a date of the end of March or early April in 1 BC as the proper date of death for Herod. However, since the birth of Jesus is not known with accuracy, we will set aside any issues associated with the lack of clarity of Herod's death year.
Seasonality of the conjunction
It should be noted that the key conjunctions occurred in summer months, not on December 25th; however, one must recall that the date of December 25th is a later construct for the date of the birth of Jesus. The Gospels are, of course, silent as to the day of the year of the birth. Summertime actually fits well to the circumstances reported in the Scriptures, since the shepherds tending their flocks would likely be more active in the fields in these warmer months.
- Holy Bible. Book of Numbers 24:17
- Holy Bible. Luke 1: 1-20
- Holy Bible. Matthew 2: 1-23
- W.E. Filmer. 1966. Chronology of the Reign of Herod the Great, Journal of Theological Studies 17: 283-298
- Paul Keresztes. 1989. Imperial Rome and the Christians: From Herod the Great to About 200 AD. (Lanham, MD: University Press of America) 1-43;“The Nativity and Herod’s Death,” in Chronos, Kairos, Christos: Nativity and Chronological Studies Presented to Jack Finegan, ed. Jerry Vardaman and Edwin M. Yamauchi (Winona Lake, IN: Eisenbrauns) 85-92.
- John Mosley. 1988. The Christmas Star. Griffith Observatory. 76 pages
- Frank Ramirez. 2002. The Christmas Star (Google eBook) CSS Publishing. 40 pages
- Emil Schürer. 1896. A History of the Jewish People in the Time of Jesus Christ, 5 vols. New York, Scribner’s.
- Andrew Steinmann. 2009. When Did Herod the Great Reign? Novum Testamentum, Volume 51, Number 1, 2009 , pp. 1-29(29) [Argues that Herod died in 1 BC]
. Star of Bethlehem