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Leonids(lee -ŏ-nidz) (November swarm) A periodic meteor shower that tends to be insignificant most years (ZHR about 10) but at 33-year intervals produces a spectacular meteor storm. The shower, radiant: RA 152°, dec +22°, maximizes on the two days around Nov. 17 each year. The associated meteoroid stream is the dust debris from comet Tempel-Tuttle (1866 I) and storms occur when the Earth intersects the stream near the parent comet. This comet has an orbital period of 33 years. The last storm occurred in 1999. Spectacular storms occurred in 1799, 1833, 1866 and also in 1996; 1899 and 1933 were years of only mediocre displays.
a meteor shower whose radiant is in the constellation Leo. Observed in the middle of November, the Leonids are related to the comet 1866 I, which has a period of 33 years. The dense swarm of meteoric bodies occupies a small part of the comet’s orbit; meteor showers were observed during the comet’s encounters with the earth in 1799, 1833, 1866, and 1966. An insignificant number of meteors have been evident in other years.