The Constellations and the Fixed Stars

The earliest Ancient Near Eastern views on the cosmos imagined it to be box- or cylinder-shaped and consisting of seven layers or “heavens”.

Echo’s of this ancient worldview can be found in the tent-shaped cosmos referred to in the Old Testament (Psalms ??:??) and the Topographia Christiana of Cosmas Indicopleustes.

The concept of a spherical cosmos with a central Earth, surrounded by concentric spheres containing the Sun, Moon, planets and the fixed stars probably originated in the 5th century BCE.

Cosmology & Cosmogony

Stars and Constellations

Prayer to the Gods of the Night

Text dating from the Old Babylonian period which refers to the Arrow (Sirius), the Yoke Star (Arcturus), the Stars (Pleiades), the True Shepherd of Anu (Orion), the Dragon (Hydra?), the Wagon (Ursa Major), the Goat Star (Wega) and the Bison (Ophiuchus/Serpens). The text is known in three versions: Old Babylonian (c. 1700 BC), Hittite (c. 1200 BC) and Assyrian (c. 700 BC).

The Babylonian Creation Myth (Enūma eliš)

The Babylonian Creation Myth Enūma eliš (“When on high”) was recited annually on the 4th day of the New Year Festival held in Babylon during the first twelve days of the month of Nisan. It describes how the god Marduk rose to kingship among the gods by defeating the forces of chaos, personified by the sea, Tiamat. Subsequently, he organised the universe and built the city of Babylon as the earthly residence of the gods.

The recovery of the statue of Marduk from Susa by Nebuchadnezzar I ( 1125-1104 BC), after it had been removed from Babylon by the Elamite king Kutir-Nahhunte (c. 1155 BC), may have been the occasion for composing the text.

The Astronomical Compendium MUL.APIN

Although the significance of this compendium was already noted by Bosanquet and Sayce in 1880, the first partial edition [tablet I = BM 86378] was not published until 1912. The first edition with a modern translation and commentary of both tablets was published in 1989.

The earliest copies of this compendium date from 687 BC, and it is generally assumed that it includes observational material dating from around 1200-1000 BC. Some scholars claim a much earlier epoch for this material and suggest that it may date from the late 3rd millennium BC (cf. the publications by Papke & Tuman).

Identification of the Arrow Star

One of the earliest star names to be recognized on cuneiform tablets was the Arrow Star (initially transliterated as kakkab míšrî, later as kaksidi or mul gag-si-sá). Its description on the so-called “Broken Obelisk” inscription, first dated to the reigns of the Assyrian rulers Tiglath-Pileser I (1114-1076 BC) or Assurnasirpal II (883-859 BC) but now more probably to that of Assur-bel-kala (1073-1056 BC), as rising “glowing as molten copper in the days of cold and frost”, gave rise to several widely different identifications such as:

Following Weidner’s analysis of the then available texts in 1912, most authorities have adopted the identification with the star Sirius (sometimes combined with the nearby star Procyon and other more southern stars to form the constellation of a Celestial Archer).

The “Hilprecht Text” and Related Texts

The Zodiac and the Paths of Anu, Enlil and Ea

The Babylonian zodiac was sidereal, i.e. longitudes were not measured from the vernal equinox (the intersection with the celestial equator), but from a small number of bright fixed stars near the ecliptic. The most important reference stars appear to have been Aldebaran (defining 15º Taurus), Pollux (0º Cancer), Regulus (5º Leo), Spica (0º Libra), Antares (15º Scorpius) and Deneb Algedi (0º Aquarius).

??? ??? Aries Ari     0º –   30º
    Taurus Tau   30º –   60º
    Gemini Gem   60º –   90º
    Cancer Cnc   90º – 120º
    Leo Leo 120º – 150º
    Virgo Vir 150º – 180º
    Libra Lib 180º – 210º
    Scorpius Sco 210º – 240º
    Sagittarius Sgr 240º – 270º
    Capricornus Cap 270º – 300º
    Aquarius Aqr 300º – 330º
    Pisces Psc 330º – 360º

Note that some authors prefer to use non-standard constellation abbreviations such as Can (= Cancer), Sag (= Sagittarius), Aqu (= Aquarius) and Pis (= Pisces). Those given in the above table are the constellation abbreviations recommended by the International Astronomical Union

Although Hellenistic astronomers based their measurements and theories on a tropical zodiac (longitudes measured from the First Point of Aries), Hellenistic astrological tables and horoscopes indicate that the sidereal zodiac was employed up to the end of the 5th century AD.

Pre-Hipparchian Knowledge of the Precession of the Equinoxes

The question whether Babylonian astronomers were aware of the precession of the equinoxes or whether it was first discovered by Hipparchus of Nicaea has been hotly debated in the past.

Studies of luni-solar and planetary longitudes mentioned in Late-Babylonian horoscopes and diaries have revealed that they are always measured from a fixed position with respect to the stars and are therefore based on a sidereal zodiac. The use of a sidereal zodiac was continued by many astrologers of the Hellenistic and Roman Period.

The following diagram, based on the data in Kollerstrom (2001), plots the longitude offsets as found in Late Babylonian horoscopes (purple data points) and Greek horoscopes (blue data points) with respect to the tropical zodiac. The slope of the weighed least-squares fit through the data is equivalent with a longitude shift of one degree in 75.4 years. Around the year AD 307 the astrologers’ sidereal zodiac coincided with the tropical zodiac.

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