The author discusses the importance of astronomy for the study of the Roman mithraism, especially for the interpretation of the bull-slaying cult icon. He gives the review of the opinions that considered this cult image as a star map. He agrees with Speidel and Ulansey that the figures on the bull-slaying scene correspond to equatorial constellations. Speidel's statement that Mithras double can be found in Orion constellation, the author considers erroneous because of the mythological and iconographic incompatibilities between Mithras and Orion. The author emphasizes that the Graeco-Roman world imagined Taurus constellation as a representation of a bull head alone (or sometimes with the front feet). Hence the author opines that the rest of the bull's body - visible in the cult image - symbolizes the ecliptic. A shiny star Spica, placed in the ecliptic, on the bull-slaying scene is represented with the grain-spike at the end of the bull's tail. Cultural and historic circumstances conditioned the iconographic similarities between Perseus and Mithras. Ulansey opines that Mithras figure stands for Perseus. The author disagrees with him because this constellation is situated neither in equator nor in ecliptic. The cult image presents a very ancient symbol of struggle between lion and bull, and in it Mithras replaced Leo constellation. Mithras is connected with Leo constellation through the leontocephalic deity, but he cannot be identified with this constellation. The author concludes that it is possible to follow associated and consistent astral symbolism on the Mithric bull-slaying motif. The skeleton for the structure of the whole image consists of the two celestial circles - equator and ecliptic - with appertaining figures-constellations.
