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κομήτης (ἀστήρ)
see also:
κομήτης (ἀστήρ), crinitus, -a, -um [Seneca]
comet
Aristotle METE
κομήτης (ἀστήρ)
DEF: diffused equally on every side I 7.344a22;
• [dox.] Aeschylus I 6.343a16; Anaxagoras I 6.342b28; Democritus I 6.342b28, 343b26; Hippocrates of Chios I 6.343a16, cf. 7.344b16;
• analogy I 7.344a32;
• and akin phenomena I 3.339a35;
• and place I 1.338b23, 6.343a24, 343a36, 8.346a14, 346b13;
• and stars I 6.343b32, 7.344b10;
• and the milky way I 6.342b25;
• as planet I 6.343a23, 8.346a3;
• as reflection I 7.344b13, 8.345b12.
• bearded (pōgōnias) I 7.344a22;
• constitution of I 7.344b1, 345a6, 8.345b35, 346b8;
• event I 6.343b1, cf. 7.344b35, 6.343b5, Ι 7.344b33, 345a2-3;
• people I 6.343a23, 8.345b12;
• shape of I 7.344a21;
• visible I 6.343a34, 7.344a35, 8.346b1;
Lucretius DRN
[not attested]
Seneca NQ
cometes, -ae
-
DEF: cf. I 15.4.3;
• [dox.] Apollonius of Myndus VII 4.1.3, 17.1.2-5; Aristotle VII 5.4.1, 5.5.2, 28.1.1; Charmandros VII 5.3.2; Conon VII 3.3.3; Epigenes VII 4.1.5-6, 6.1.1, 9.1.4-6, 6.3.2; Ephorus VII 16.2.5; Eudoxus VII 3.2.6; Panaetius VII 30.2.2-3; people VII 19.1.4, 21.1.1, 26.1.1, 26.2.2, cf. 29.3.8; Posidonius VII 20.4.3;
• analogy VII 18.2.3;
• and fixed laws VII 25.3.1;
• and heavenly bodies VII 2.1.1, 8.4.4, 18.1.2;
• and moving star VII 12.2.3, VII 12.3.5-4.1;
• and nature VII 27.6.1-2;
• and place VII 7.1.7-8, 11.1.3, 12.8.8;
• and season VII 30.2.5.
• and the zodiac VII 24.2.2;
• and whirlwind VII 8.2.2-7;
• and wind VII 7.1.2, 7.3.6, 28.2.2;
• as reflection VII 19.1.4;
• as sign VII 28.2.2; 30.2.2-3;
• body of VII 26.2.7;
• constitution of VII 21.1.1, cf. 22.1.1;
• duration of appearance VII 12.4.8, 12.8.7, 23.3.5, 29.2.3;
• eternal VII 22.1.1, 27.2.4;
• event VII 15.1.5, 15.2.1, 16.2.5, 17.2.5, 23.1.5, 28.3.1;
• fiery body VII 1.5.1;
• in pieces VII 16.3.2-3; size VII 18.1.2;
• kinds of VII 11.2.5, 11.3.8;
• motion of VII 8.3.3-4, 18.1.6, 21.2.1, 22.2.2-3;
• rare VII 14.4.11, 25.3.1;
• recording VII 3.1.1, cf. 25.7.6;
• see through VII 18.2.3, 26.1.1;
• shape of VII 5.4.4, 26.2.2-7, 27.4.4;
• visible VII 10.1.7-2.1, 20.4.1;
References for Greek and Latin
[only for the Greek lemma]
Heidarzadeh, T. (2008) A History of Physical Theories of Comets. From Aristotle to Whipple, Springer, pp. 1-19.
Barrett, A. A. “Observations of Comets in Greek and Roman Sources before A.D. 410.” Journal
of the Royal Astronomical Society of Canada 2 (1978), 81–106.
—— .“Aristotle and Averted Vision.” Journal of the Royal Astronomical Society of Canada 4
(1977), 327.
[only for the Latin Lemmata]
Heidarzadeh, T. (2008) A History of Physical Theories of Comets. From Aristotle to Whipple, Springer, pp. 21-23.
Modern Description
written by Susanne M Hoffmann
Since Tycho Brahe (around 1600 CE) it is known that comets are farther away from the Earth than the Moon. Tycho successfully measured the distance to a comet.
Comets are objects of the solar system. They are small objects with typical diametres of a few kilometres and orbits that are either elliptical (with excentricity), paraboloic or hyperbolic.
They consist of stone and frozen gases and are, therefore, often called "dirty snowballs". In the vicinity of the Sun, the gases sublimate, form a so-called "coma" (like a thin atmosphere) around the rocky comet core and are blown away from the core by the solar wind because the gravitation of the small object is low. The solid state material (grains of stone/ sand, pebbles, dust) is swepted along with the blown away gas.
Due to electric forces of the plasma of the solar wind, the gas and the dust particles of the comet are blown to different directions and separated. Modern photographs clearly show the gas tail as bluish and the dust tail as whitish but the naked eye observer is not able to distinguish the colours of the tail(s).
Further Remarks