Caesar's Comet
Encyclopedia
44
Year 44 was a leap year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Crispus and Taurus...
BC
Anno Domini
and Before Christ are designations used to label or number years used with the Julian and Gregorian calendars....
– was perhaps the most famous comet of antiquity. The seven day visitation was taken by Romans as a sign of the deification of the recently dead dictator, Julius Caesar
Julius Caesar
Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....
(100
100
Year 100 was a leap year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Traianus and Frontinus...
-44 BCE).
Caesar's Comet was one of only five comets known to have had a negative absolute magnitude and was possibly the brightest daylight comet in recorded history. It was not periodic and may have disintegrated.
History
Caesar's Comet was known to ancient writers as the Sidus Iulium ("Julian Star") or Caesaris astrum ("Star of CaesarJulius Caesar
Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....
"). The bright, daylight-visible comet
Great comet
A Great Comet is a comet that becomes exceptionally bright. There is no official definition; often the term will be attached to comets that become bright enough to be noticed by casual observers who are not actively looking for them, and become well known outside the astronomical community. Great...
appeared suddenly during the festival known as the Ludi Victoriae Caesaris
Ludi
Ludi were public games held for the benefit and entertainment of the Roman people . Ludi were held in conjunction with, or sometimes as the major feature of, Roman religious festivals, and were also presented as part of the cult of state.The earliest ludi were horse races in the circus...
– for which the 44 BC iteration was long considered to have been held in the month of September (a conclusion drawn by Sir Edmund Halley). The dating has recently been revised to a July occurrence in the same year, some four months after the assassination of Julius Caesar
Assassination of Julius Caesar
The assassination of Julius Caesar was the result of a conspiracy by approximately forty Roman senators who called themselves Liberators. Led by Gaius Cassius Longinus and Marcus Junius Brutus, they stabbed Julius Caesar to death in the Theatre of Pompey on the Ides of March 44 BC...
, as well as Caesar's own birth month. According to Suetonius
Suetonius
Gaius Suetonius Tranquillus, commonly known as Suetonius , was a Roman historian belonging to the equestrian order in the early Imperial era....
, as celebrations were getting underway, "a comet shone for seven successive days, rising about the eleventh hour, and was believed to be the soul of Caesar."
The Comet became a powerful symbol in the political propaganda that launched the career of Caesar's great-nephew (and adoptive son) Augustus
Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...
. The Temple of Divus Iulius (Temple of the Deified Julius) was built (42 BC) and dedicated (29 BC) by Augustus for purposes of fostering a "cult of the comet". (It was also known as the "Temple of the Comet Star".) At the back of the temple a huge image of Caesar was erected and, according to Ovid
Ovid
Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria...
, a flaming comet was affixed to its forehead:
To make that soul a star that burns forever
Above the Forum and the gates of Rome.
Modern scholarship
In 1997, two scholars at the University of Illinois at ChicagoUniversity of Illinois at Chicago
The University of Illinois at Chicago, or UIC, is a state-funded public research university located in Chicago, Illinois, United States. Its campus is in the Near West Side community area, near the Chicago Loop...
– John T. Ramsey (a classicist) and A. Lewis Licht (a physicist) – published a book comparing astronomical/astrological evidence from both Han China
Han Dynasty
The Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...
and Rome. Their analysis, based on historical eye-witness accounts, Chinese astronomical records, astrological literature from later antiquity and ice core
Ice core
An ice core is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from high mountain glaciers elsewhere. As the ice forms from the incremental build up of annual layers of snow, lower layers are older than upper, and an ice...
s from Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
s, yielded a range of orbital parameters for the hypothetical object. They settled on a 0.224 A.U.
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
orbit for the object which was apparently visible with a tail from the Chinese capital
Chang'an
Chang'an is an ancient capital of more than ten dynasties in Chinese history, today known as Xi'an. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" ; yet after its fall in AD 23, the old name was restored...
(in late May) and as a star-like object from Rome (in late July).
A few scholars, such as Robert Gurval of UCLA and Brian G. Marsden
Brian G. Marsden
Brian Geoffrey Marsden was a British astronomer born in Cambridge, England, and educated at The Perse School in Cambridge, New College, Oxford and Yale University. Dr...
of the Harvard-Smithsonian Center for Astrophysics
Harvard-Smithsonian Center for Astrophysics
The Harvard–Smithsonian Center for Astrophysics is one of the largest and most diverse astrophysical institutions in the world, where scientists carry out a broad program of research in astronomy, astrophysics, earth and space sciences, and science education...
, leave the comet's very existence as an open question. Marsden notes in his forward to Ramsey and Licht's book, "Given the circumstance of a single reporter two decades after the event, I should be remiss if I were not to consider this [i.e., the comet's non-existence] as a serious possibility."
- May 18, 44 BC (ChinaChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
) - July 23–25, 44 BC (RomeRomeRome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
) - Absolute magnitude: −4.0
In literature
Ovid describes the deification of Caesar in Metamorphoses (8 AD):Then Jupiter, the Father, spoke..."Take up Caesar’s spirit from his murdered corpse, and change it into a star, so that the deified Julius may always look down from his high temple on our Capitol and forum." He had barely finished, when gentle Venus stood in the midst of the Senate, seen by no one, and took up the newly freed spirit of her Caesar from his body, and preventing it from vanishing into the air, carried it towards the glorious stars. As she carried it, she felt it glow and take fire, and loosed it from her breast: it climbed higher than the moon, and drawing behind it a fiery tail, shone as a star.
In Shakespeare’s Julius Caesar
Julius Caesar (play)
The Tragedy of Julius Caesar, also known simply as Julius Caesar, is a tragedy by William Shakespeare, believed to have been written in 1599. It portrays the 44 BC conspiracy against...
(1599), Caesar's wife remarks on the fateful morning of her husband's murder
Assassination of Julius Caesar
The assassination of Julius Caesar was the result of a conspiracy by approximately forty Roman senators who called themselves Liberators. Led by Gaius Cassius Longinus and Marcus Junius Brutus, they stabbed Julius Caesar to death in the Theatre of Pompey on the Ides of March 44 BC...
: "When beggars die there are no comets seen. The heavens themselves blaze forth the death of princes."