(meteorobs) quads maximum

[Thomas Ashcraft]

kcstarguy at aol.com wrote:
> Aren't the quads predicted to have maximum around 7 am Eastern timein US? on Jan 3? I am getting differing points of view for the time of the maximum and whether it is morning of 3rd or 4th?
>
>
> Dr. Eric Flescher 
>   


Eric,

Here is info from the 2009 IMO meteor shower calendar:
http://www.imo.net/calendar/2009
::::::

The waxing crescent Moon will set near local midnight for the maximum of 
the Quadrantids at northern hemisphere sites, from many of which, the 
shower's radiant is circumpolar, in northern Boötes. As this area 
attains a useful elevation only after local midnight, rising higher in 
the sky towards morning twilight, this is excellent news. However, the 
expected peak's timing falls poorly for land-based observers, except for 
those in the extreme western areas of North America, on islands in the 
North Pacific Ocean, and the extreme east of Russia. An interesting 
challenge is to try spotting the occasional long-pathed shower member 
from the southern hemisphere around dawn, but sensible Quadrantid 
watching cannot be carried out from such places.

The maximum timing above is based on the best-observed return of the 
shower ever analysed, from IMO 1992 data, confirmed by radio results in 
most years since 1996. The peak itself is normally short-lived, and 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, 
but some genuine variability is probably present too. For instance, 
visual ZHRs in preliminary results from 2008 persisted for more than two 
hours at close to their best, with the maximum itself centred around 
three to four hours later than anticipated. An added level of complexity 
comes from the fact that 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, but 
apparently not all, years since 2000 seem to have produced a, primarily 
radio, maximum following the main visual one by some 9-12 hours. Visual 
confirmation of any repeat near this time in 2009 would fall ideally for 
sites from Europe east to central Asia. Oddly, in 2008, there seemed to 
be two possible radio Quadrantid peaks, but the first was apparently 
about six hours /before/ the visual one, during an apparent 
rates-plateau ahead of the main maximum in the visual data.

Past observations have suggested the QUA radiant is diffuse away from 
the maximum, contracting notably during the peak itself, although this 
may be a result of the very low activity outside the hours near maximum. 
Still-imaging and video observations from January 1-5 would be 
particularly welcomed by those investigating this topic, using the IFCs 
and TFCs given above, along with telescopic and visual plotting results.

::::::::::



>
>