The Solar Longitude (Abbrev: S.L., λ ☉) is 271 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 Ursids radiate out from the Ursa Minor constellation rather than the larger Ursa Major, both the bear constellations. The radiant point is near the Kochab, also known as Beta Ursae Star. The associated comet is believed to be 8P/Tuttle which is due back in 2021 but shouldn`t hold out too much hope for a spectacular event as the last one wasn`t as expected.
The source of the meteor shower is 8P/Tuttle. The closest star to the radiant point of the meteor shower is Kochab. The coordinates can also be determined by the Right Ascension (219.9) and the Declination (75.4).
The Zenith Hourly Rate or how many you expect to see during the hour is 10. The ZHR can radically increase if the comet or associated object is close by. The speed/velocity of the Meteor Shower particles is 33 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||Kochab|
|Max Activity Date||22 Dec|
|Activity Period||December 17-25|
|Solar Longitude / λ ☉||271 °|
|Zenith Hourly Rate||10|