Abbreviations and Glossary

SYLLECTA CLASSICA 17 (2006) 47 SYMBOLS an object that can be classified as a comet with some certainty. an object that may or may not be a comet. N a report by a possible eyewitness. * ** *** possible corroborating, non-European source 1 (*), 2 (**), 3 (***), etc. ABBREVIATIONS AND GLOSSARY The names of Classical authors and their works are abbreviated as in the Oxford Classical Dictionary, 3rd ed. (1996) or in the Oxford Latin Dictionary or Liddell-Scott-Jones, Greek-English Lexicon, when not in the OCD. AU (astronomical unit) approximately the average distance between the sun and earth (c. 92,956,000 mi.). B Barrett (1978) the number (B1, B2, etc.) referring to the corresponding record in his collection of 62 numbered objects. Bolide (fireball) bright meteor ranging in magnitude from that of Venus when daylight visible (-4) to occasionally many times the brightness and size of the full moon (-12.7). Often the passage of these objects is accompanied by a loud boom (see Object 9a, 91 B.C.). The term bolide is generally ap- 48 SYLLECTA CLASSICA 17 (2006) plied to a fireball that explodes. The chief difference that distinguishes a bolide or fireball from a meteorite is that the former does not come into contact with the earth except as fine dust or debris, whereas a meteorite reaches the earth as a solid object. chang a Chinese unit of linear measurement, = 10 ch’ih, = approx. 10 deg. ch’ih a Chinese unit of linear measurement, = approx. 1 deg. mag. magnitude, +6 being the faintest degree visible to the naked eye; each unit on this scale amounts to a difference in brightness of 2.512x; objects brighter than +1 have negative numbers (e.g. full moon = -12.7; Venus, when daylight-visible, = -4). 1P/Halley the standard designation of Halley’s Comet as the first comet to be identified as periodic. Radiant the point or area of the heavens from which a stream of meteors appears to emanate . Sungrazer a comet that nearly collides with the sun, passing within 100 to 400 thousand miles of the sun’s surface. tu a Chinese unit of angular measurement, = approx. 1 deg. ...