All together now.The resonance discovered in the star HD 202206 system is not unique, and it isn't true that "[t]his particular synchrony synchrony /syn·chro·ny/ (-krah-ne) the occurrence of two events simultaneously or with a fixed time interval between them. atrioventricular (AV) synchrony has never been seen before in a planetary system planetary system, a star and all the celestial bodies bound to it by gravity, especially planets and their natural satellites. Until the last decade of the 20th cent. " ("Extrasolar Planet News: Super-planet or brown dwarf?" SN: 11/27/04, p. 341). Resonances abound in the solar system. The orbital periods of the Galilean satellites of Jupiter, many asteroids' orbits, Jupiter's orbit, and Pluto's orbit with Neptune are some examples. Resonances also exist in numerous extrasolar ex·tra·so·lar adj. Being or originating outside the solar system an extrasolar planet. systems discovered over the past 10 years. Also, the extrasolar system around HD 37124 that consists of two planets with periods of 155 and 31 days shows a 5:1 mean motion resonance, so even the particular commensurability com·men·su·ra·ble adj. 1. Measurable by a common standard. 2. Commensurate; proportionate. 3. Mathematics Exactly divisible by the same unit an integral number of times. Used of two quantities. seen for HD 202206 is not new. DEREK WALLENTINSEN, SAN PEDRO, CALIF. |
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