The Solar Longitude (Abbrev: S.L., λ ☉) is 140 degrees, this value is the the date of maximum activity. It is measured as a degree with zero degree indicating spring equinox (roughly March 21st/22nd). 90 is the Summer Solstice, 180 is the Autumn Equinox and 270 is the Winter Solstice. This degree is independent of the calender. AMS .
The Perseids are one of the brightest meteor Showers in the year coupled with a high rate per hour which hopefully won`t be a let down when they do come about. The Perseids are are associated with the Swift-Tuttle comet which is a mid-range comet, taking 133 years to complete its orbit. The Radiant Point location is Miram near the border with Cassiopeia who in the Grecian Legend is the mother of Andromeda who Perseus saved from being killed by Cetus.
The source of the meteor shower is 109P/Swift-Tuttle. The closest star to the radiant point of the meteor shower is Miram. The coordinates can also be determined by the Right Ascension (48.2) and the Declination (58.1).
The Zenith Hourly Rate or how many you expect to see during the hour is 100. The ZHR can radically increase if the comet or associated object is close by. The speed/velocity of the Meteor Shower particles is 59 km/s. The population index of the meteor shower is 3. The population index refers to the magnitude distribution of the meteorites, the smaller the index, the brighter the meteors are, the higher, the dimmer the meteors are. For this particular meteor shower, bright meteors are more frequent.
|Closest Star to Radiant Point||Miram|
|Max Activity Date||12 Aug|
|Activity Period||July 23-August 22|
|Solar Longitude / λ ☉||140 °|
|Zenith Hourly Rate||100|