峰值在11月19日5:30，ZHR＝50，持续一天。
2003: THE "FIREBALL SHOWER" NOVEMBER 19
November 19, 05:30 UT (1 day wide), rates peak at ZHR = 50
According to Peter Jenniskens and Hans Betlem (2000, ApJ 531, 1161), many other such old dust trails trapped in mean-motion resonances tend to form a broad dust trail structure called the "FILAMENT". The Filament is a sum of contributions from many returns and the nature of individual dust trails may not be recognized anymore. In that case, the structure will be very broad, about 1 day wide and underlays more recent dust trail encounters (see figure). The Filament was first seen in 1994. The Filament is expected to stop being visible 10 - 11 years (little less than 1 orbit of Jupiter) after the first sighting in 1994. There is a good chance that the Filament will return in 2003 (which would span 10 years), but it may be just beyond the maximum range over which dust is protected from close encounters with Jupiter. If still in the protected range, then rates in 2003 could increase to about ZHR = 50 per hour (nearly like a Perseid shower, but more rich in bright meteors...). Peter Jenniskens calculated an expected peak time around 5.5 UT, November 19, based on the trend observed in 1995-1997 and 1999-2002. This corresponds to solar longitude 236.407 (J2000). However, in 1994 and 1998 this peak was ~ 0.7 days earlier for unknown reasons. If the prediction holds, then the best viewing is in the Americas, but bright meteors can also be seen in other parts of the world in the nights of Nov. 17/18, 18/19, and 19/20. The Moon will be beyond last quarter, but can still interfer with the viewing in the early morning hours. On the other hand, the Filament tends to be rich in bright meteors and should still give a good showing if the particles have not been scattered by Jupiter. Observe away from the Moon, best from a location in the Moon's shadow with as wide a field of view and good viewing near the horizon.
In addition to this, Jeremie Vaubaillon pointed out that one particular trail, from 1533, will peak around 07:27 UT, with an expected ZHR of about 100. Joe Rao pointed out that the previous return, in 1965, showed Filament-type activity in 1971, about as far from the comet's passage as this year:
In Sky & Telescope, January 1972, page 57, the 1971 Leonids were described as producing "moderate" activity with up to 27 per hour for an observer in North Carolina. Others reported a number of bright fireballs.
In the February 1973 S&T, page 127, Karl Simmons of Jacksonville, Florida passed along a report of the 1972 Leonids producing 40 per hour obtained by a team stationed at Ottawa, Ontario. "The Leonids evidently had their best display since 1966 this year, and the stream is still active," he wrote.
And finally, in the March 1975 S&T, page 193, the 1974 Leonids were described as "startling" by Norman W. McLeod of Punta Gorda, Florida. He had Leonid rates of up to 40 per hour and about half of the 179 Leonids that he witnessed left trains, in some cases up to 3 minutes. Another report, from Virginia Beach cited the train left by a blue fireball that lasted for up to eight minutes! Keep in mind that this 1974 display occurred more than nine years after the 1965 perihelion of 55P!
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