What relationship could exist between the stars and coins in the ancient world? Apparently none if we think that astronomy, or rather the observation of phenomena in the sky, was born several centuries before the first interest of scholars in coins as a source of historical information.
But the Greeks and Romans had nevertheless combined the two aspects.
It must be said at once that the Greeks remained unsurpassed for a long period for their discoveries in astronomy and the Romans were mediocre pupils. All knowledge on the subject came to Rome from the Hellenistic world. Fate, astrology and astronomy were in the belief of the ancients closely connected: the Astrological Fate or the Astral Necessity.
It is better to avoid the eternal debate between the ineluctable Fate and the blind and distracted Fortune, which has seen great names in opposition, but, judging from the documentation that has come down to us, it seems certain that most of the ancient population, including many educated men, was convinced of the influence of the stars.
The ancients, in fact, were convinced that the Sun and the Moon, as well as all the other stars and planets (seven of them were known at the time, while the other two, Neptune and Pluto, the most distant, were discovered later) through their movement influenced the life, death, fate and fortunes of mankind.
Julius Caesar Octavian, the adopted son of Caius Julius Caesar, was born on September 23, 63 BC.
He reminds us of this himself in a letter, quoted by Aulus Gellius, dated "IX Kal. Octobris" nine days before the kalends of October": my dearest ... I would have hoped that you would be here with me today to celebrate my sixty-fourth birthday". The letter is addressed to his nephew Caius, son of Julia, an impossible letter because it refers to the year 3 AD while the nephew had died seven years earlier, in 4 BC. The information of Augustus' date of birth is confirmed by the poet Manilius "sub pondere Librae".
September 23 corresponds to the first day of the new sign of the zodiac, Libra, Libra, a new sign that, abandoning the Chaldean Zodiac with 11 figures, was introduced between Virgo and Scorpio in the calendar reform, which came into force in 46 BC by his adoptive father Caesar. It seems possible to affirm that there was a precise will, an interest at the communicative level to give this event, the date of Augustus' birth, a religious and mythical value.
So Augustus' zodiac sign is Libra. But no, it's Capricorn.
The famous Augustan gem from Vienna depicts, in the centre, Augustus seated among the gods, in the lower register a scene of the raising of a trophy with the presence of prisoners, while at the top, between Athena and Augustus is the zodiac sign of Capricorn.
A confirmation is in the coinage of Augustus in which the same Capricorn appears in the aurei and denarii.
The explanation lies in the belief of the ancients that as important as the date of birth was in fact even more important that of conception, which in Augustus coincides with the period of the sign of Capricorn (from December 22 to January 20).
In astronomy the septem Triones (seven oxen) are identified in the seven brightest stars of the constellation Ursa Major. The belief is certainly ancient because this constellation is among the first to be identified by man's curiosity. In 76 B.C. the monetary magistrate of the year, L. Lucretius Trio had silver denarii minted with the head of the Sun god, on one side, and, on the other, a lunar crescent and seven stars.
There is no doubt a connection between this coin and the constellation through, albeit with the complicity of the magistrate's surname, Trio.
Such composition had an extraordinary fortune also in the following centuries and was used by coin series of several emperors and empresses, as, to quote some examples, in denarii issued in honour of the Diva Faustina minor, wife of Marcus Aurelius, with an almost similar image in the reverses, or in coin series in the name of Septimius Severus, of his wife Iulia Domna and of his son Geta, in which the concept of Saeculi Felicitas is always insisted upon, or again in coins in the name of Diva Caecilia Paulina, wife of emperor Maximinus I the Thracian.
An analogous composition is found on a series of coins of Hadrian but in this case the stars are five.
Is it a mistake of the engraver of cones? No, certainly not, but the precise reference to a different constellation, that of Antinous, close to the celestial equator, mentioned by Ptolemy and dedicated by the emperor to his favorite with that name or more properly with that of the Eagle. The young Antinous is in fact represented in the claws of the bird dear to Jupiter. The literary tradition tells us that the emperor Hadrian, after the death of Antinous, searched the sky not only among the alignments of the stars for a pseudo-figure that could remember him but also an area where, as the ancients believed, were concentrated all those natural essences to make him appear a God. Together with his astronomers he believed he saw a space between the intermediate zone of the constellation of Aquila and Capricorn, so that Antinous would have his home in this zone and would be recognized and venerated for eternity. The main stars of the constellation of Aquila are five, as in the monetary representation.
The Dioscuri were the tutelary gods of the ancient city since 497 BC, when, after the battle of Lake Regillus won by the Romans over the Latins, the two twins, sons of Jupiter, were seen watering their horses at the Fonte Giuturna, at the foot of the Palatine.
The Dioscuri are always represented as horsemen with a star on their foreheads. This star appears on several occasions in glyptics and numismatics. Hyginus, Roman writer and astronomer, confirms(De Astronomia II, 22) that the Dioscuri were identified in the constellation of Gemini, of which, precisely, the brightest stars are two.
Nor can it be ruled out that in one of the earliest coin series issued by the mint of Rome, in an
moment in which the divinities still had the exclusivity of the monetary representation, the two stars that appear next to the lunar crescent, and on the other side of the frontal head of the Sun, are not to be referred just to the Dioscuri.
We can close with an issue in the name of Julia Maesa of the mint of Amastris in Paphagonia, with the representation of the complete zodiac with in the center the representation of Jupiter and Juno.