New Insights into the Nature and Orbital Motion of Aristotle's Comet in 372 BC

Abstract

Extending the investigation of the presumed primordial comet as part of continuing work on a new model of the Kreutz sungrazer system, I confront a previously derived set of orbital elements with Aristotle's remarks in his Meteorologica to test their compatibility and determine the comet's perihelion time. The two translations of the treatise into English that I am familiar with differ at one point substantially from each other. Unambiguously, the year and season of the comet's appearance was early 372 BC (or -371). From Aristotle's constraint on the comet's setting relative to sunset, I infer that the probable date of perihelion passage was January 20, a date also consistent with the vague remark on frosty weather. On the day that Aristotle claims the comet was not seen, its head may have been hidden behind the Sun's disk or in contact with it. The observation that the `comet receded as far as Orion's belt, where it dissolved' is being satisfied by the tested orbit if the perihelion was reached between January 20 and February 10. Aristotle's third statement, which describes the tail as a streak 60 degrees in length, suggests a plasma feature stretching in space over 0.8 AU. The dust tail was developing more gradually and it was all that could be seen from the comet when it was approaching Orion's belt in early April. The comet was seen over a period of more than 10 weeks. The results of this study strengthen the notion that Aristotle's comet indeed was the gigantic progenitor of Kreutz sungrazers.