British Astronomical Association
	Meteor Section

1999 Leonids

Much of the UK was unfortunately clouded out for the long-awaited peak of the 1999 Leonids on November 17-18. Observers who travelled overseas fared rather better, notably in Spain, Portugal, Greece, Cyprus and the Sinai Desert in Egypt. A general overview of the Sinai expedition is given in the Leonid pages in the main BAA site.

Thanks to their sheer volume, analysis of the various data sets from itinerant observers is still in progress, many months after the event! Given here in graphic form is a detailed breakdown of several observers’ results from Sinai, in five-minute intervals. The Leonid storm did, indeed, occur, reaching a peak equivalent ZHR of about 2600 around 0158 UT on 1999 November 18d. The most intense activity was found in a two-hour interval centred on this time. Sub-peaks and other structure, reflecting the filamentary nature of the Leonid meteor stream, are evident from the observations, and can be tied to ejection of populations of meteoroids from Comet 55P/Tempel-Tuttle at different past returns to the inner solar system. Some observers in Scotland and the north of England caught glimpses of the highest activity through gaps in the cloud. Overall, however, observed Leonid rates for those who stayed at home in the British Isles were rather low on the nights before and after maximum in 1999. Observers in the UK may get another chance, albeit under strongly moonlit conditions, on 2000 November 18, around 0345 UT...

Page last updated: 31/08/2005