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: http://star.arm.ac.uk/~dja/papers/abs14MNL.html
Дата изменения: Mon Dec 23 17:27:17 2013
Дата индексирования: Fri Feb 28 01:25:48 2014
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Поисковые слова: ultraviolet
Meteor showers on Earth from sungrazing comets A. Sekhar and D.J. Asher
MNRAS, 437, L71-L75 (2014)
Abstract:
Sungrazing comets have always captured a lot of interest and curiosity among
the general public as well as scientists since ancient times. The perihelion
passage of comet C/2012 S1 (ISON) at the end of this year (on 2013 November
28) is an eagerly awaited event. In this work, we do a mathematical study to
check whether meteoroids ejected from this comet during its journey around
the Sun can produce spectacular meteor phenomena on Earth. Our calculations
show that although the orbital elements of this comet are much more
favourable than for most sungrazers to have its descending node near the
Earth's orbit, even ejection velocities as high as 1 km s-1 do not induce
sufficient nodal dispersion to bring meteoroids to Earth intersection during
present times. A similar result applies to Newton's comet C/1680 V1 which has
surprisingly similar orbital elements, although it is known to be a distinct
comet from C/2012 S1. Our analysis also shows that for meteoroids ejected
from all known sungrazing groups during recent epochs, only the Marsden
family (with required ejection velocities of some hundreds of m s-1) can
produce meteor phenomena during present times. In a broader sense, we
indicate why we do not observe visually brilliant meteor showers from
frequently observed sungrazers.