Perseids

(pûr`sēĭdz'): see meteor showermeteor shower,
increase in the number of meteors observed in a particular part of the sky. The trails of the meteors of a meteor shower all appear to be traceable back to a single point in the sky, known as the radiant point, or radiant.
..... Click the link for more information. .

Perseids

(per -see-idz) A major meteor shower, radiant: RA 47°, dec +58°, maximizing on Aug. 12 with a zenithal hourly rate (ZHR) of about 80. Perseid meteors can be seen throughout the two weeks each side of maximum and are bright and flaring, with fine trains. The geocentric velocity of the meteoroids is about 60 km s^–1. The meteoroid stream is closely associated with comet Swift–Tuttle (1862 III), which returned to the inner Solar System in late 1992. Although the display is regarded as being constant in hourly rate there are exceptions, a ZHR of 250 being observed in 1921 and 1992 and a ZHR of less than 10 in 1911 and 1912. The shower has been regularly observed for over 100 years. The first record was in ad 36.

Perseids

a meteor stream with radiant in the constellation Perseus. The Perseids are observed from July 25 to August 20, with maximum occuring on August 12. Associated with Comet 1862 III, they are the first meteor stream for which a connection with a comet was found—by G. Schiaparelli in 1866. The Perseids are one of the most active annual showers that are observable by visual or photographic means. The stream is relatively poor in small meteors, a fact that can be explained by the comparatively small amount of fine particles in the meteor swarm. The stream has a complex structure and is divided into several branches. The Perseids have been known since the year 830.

Perseids

[′pər·sē·ədz] (astronomy) A meteor shower whose radiant lies in the constellation Perseus; it reaches a maximum about August 12.

Perseids

Visibility peaks around August 10-12Meteors, also called shooting stars or falling stars, are seen as streaks of light in the sky that result when a small chunk of stony or metallic matter enters the Earth's atmosphere and vaporizes. A meteor shower occurs when a number of meteors enters the Earth's atmosphere at approximately the same time and place. The shower's name is usually derived from the constellation (or a star within it) from which the shower appears to originate.
Since the year 36 c.e. there have been records of an annual meteor shower known as the Perseids (because it appears to originate in the constellation Perseus) that is most observable during the nights of August 10-12. Observers everywhere except the South Pole can see as many as 60 meteors an hour streak across the sky on what is often referred to as the Night of the Shooting Stars .
CONTACTS:
American Meteor Society
44017 Woodland Ct.
Callahan, FL 32011
904-879-2646
www.amsmeteors.org
SOURCES:
BkHolWrld-1986, Aug 11

单词	perseids
释义	DictionarySeePerseid Perseids Perseids (pûr`sēĭdz'): see meteor showermeteor shower, increase in the number of meteors observed in a particular part of the sky. The trails of the meteors of a meteor shower all appear to be traceable back to a single point in the sky, known as the radiant point, or radiant. ..... Click the link for more information. . Perseids (per -see-idz) A major meteor shower, radiant: RA 47°, dec +58°, maximizing on Aug. 12 with a zenithal hourly rate (ZHR) of about 80. Perseid meteors can be seen throughout the two weeks each side of maximum and are bright and flaring, with fine trains. The geocentric velocity of the meteoroids is about 60 km s^–1. The meteoroid stream is closely associated with comet Swift–Tuttle (1862 III), which returned to the inner Solar System in late 1992. Although the display is regarded as being constant in hourly rate there are exceptions, a ZHR of 250 being observed in 1921 and 1992 and a ZHR of less than 10 in 1911 and 1912. The shower has been regularly observed for over 100 years. The first record was in ad 36. Perseids a meteor stream with radiant in the constellation Perseus. The Perseids are observed from July 25 to August 20, with maximum occuring on August 12. Associated with Comet 1862 III, they are the first meteor stream for which a connection with a comet was found—by G. Schiaparelli in 1866. The Perseids are one of the most active annual showers that are observable by visual or photographic means. The stream is relatively poor in small meteors, a fact that can be explained by the comparatively small amount of fine particles in the meteor swarm. The stream has a complex structure and is divided into several branches. The Perseids have been known since the year 830. Perseids [′pər·sē·ədz] (astronomy) A meteor shower whose radiant lies in the constellation Perseus; it reaches a maximum about August 12. Perseids Visibility peaks around August 10-12Meteors, also called shooting stars or falling stars, are seen as streaks of light in the sky that result when a small chunk of stony or metallic matter enters the Earth's atmosphere and vaporizes. A meteor shower occurs when a number of meteors enters the Earth's atmosphere at approximately the same time and place. The shower's name is usually derived from the constellation (or a star within it) from which the shower appears to originate. Since the year 36 c.e. there have been records of an annual meteor shower known as the Perseids (because it appears to originate in the constellation Perseus) that is most observable during the nights of August 10-12. Observers everywhere except the South Pole can see as many as 60 meteors an hour streak across the sky on what is often referred to as the Night of the Shooting Stars . CONTACTS: American Meteor Society 44017 Woodland Ct. Callahan, FL 32011 904-879-2646 www.amsmeteors.org SOURCES: BkHolWrld-1986, Aug 11
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