Från IMO:s kalender …
http://www.imo.net/calendar/2014#qua
… har följande text hämtats:
“New Moon on January 1 creates ideal viewing conditions for the predicted Quadrantid maximum on January 3. For many northern hemisphere sites, the shower’s radiant is circumpolar, in northern Bootes, from where it first attains a useful elevation after local midnight, steadily improving through till dawn. Observing locations across the eastern half of Asia should be best-placed to record what happens in 2014, if the maximum time above is correct. However, theoretical computations by Jérémie Vaubaillon have suggested this may be earlier, around 14h UT on January 3, and that it could last for longer than usual. If so, that would shift the visible region for the peak eastwards, to the North Pacific Ocean and land areas immediately adjacent, notably the extreme west of North America, for this prediction. A protracted peak could increase the visible zone further. The λ⊙ = 283 . °16 maximum timing is based on the best-observed return of the shower ever analysed, from IMO data collected in 1992, as confirmed by radio results in most years since 1996. Typically, the peak is normally short-lived, so can be easily missed in just a few hours of poor northern-winter weather, which may be why the ZHR level apparently fluctuates from year to year. However, some genuine variability is probably present too. An added level of complexity comes from the fact mass-sorting of particles across the meteoroid stream may make fainter objects (radio and telescopic meteors) reach maximum up to 14 hours before the brighter (visual and photographic) ones, so observers should be alert throughout the shower. A few years this century seem to have produced a, primarily radio, maximum following the main visual one by some 9–12 hours too. Visual confirmation of any repeat of such behaviour would be welcomed. QUA activity tends to be very low more than a day or so from the peak, and past observations have suggested the radiant is diffuse away from the maximum too, contracting notably during the peak itself, perhaps because of this lower activity then. Imaging observations would be welcomed to help investigate this topic, along with telescopic results.”
Nedan ges dels en karta som visar radiantens position, dels grafer som visar hur ZHR-aktiviteten förlöpte under svärmens maxima 2012 och 2013. Allt enligt IMO.
M v h
Hans Bengtsson
- Kvadrantidernas radiant. IMO.
- Kvadrantidernas radiant.png (48.61 KiB) Viewed 6056 times
- ZHR för Kvadrantiderna 2012. IMO.
- Kvadrantiderna 2012.png (5.56 KiB) Viewed 6056 times
- ZHR för Kvadrantiderna 2013. IMO.
- Kvadrantiderna 2013.png (6.12 KiB) Viewed 6056 times