(meteorobs) quads maximum

meteoreye at comcast.net meteoreye at comcast.net
Fri Jan 2 13:36:35 EST 2009

The January NAMN Notes are in the process of being, well, processed, so since the peak is tonight I will copy what I wrote this month. This has not been edited by Mark, so there could be some typos.


The last major shower of the winter season occurs just as the earth reaches perihelion on January 3rd.
The Quadrantid shower has a ZHR as high as that of the Perseids and Geminids, but observing conditions are rarely as favorable. The true peak only lasts a few hours. In 2008, the eastern US was the favored location, but this year it will be best seen somewhere between the US west coast and Japan. That is an area with few points of terra firma!
The IMO gives the annual peak time as Solar Longitude 283.16, or 12:50 UT on January 3rd. Last year was pretty well covered by eastern and central US NAMN members (10 total), indicating a peak from Solar Longitude 283.244 to 283.329, about 2 hours later. In fact this is probably one of the top few Quadrantid peaks with substantial coverage. At the NJAA, there were two experienced observers and we showed a peak rate toward the end of the period mentioned above. The IMO peak ZHR was shown at SL 283.285 (ZHR 82 +/-8) or 0936 UT, while NJAA observations by Wayne Hally and Pierre Martin showed a peak ZHR of 91 +/-10 at SL 283.329 (1039 UT). Pierre drove from Ottawa to New Jersey for the clear skies and the warmth; after all it was a balmy 12 degrees F! To view the IMO visual data (preliminary only) see: http://www.imo.net/live/quadrantids2008/
Based on the “normal” peak and last year’s timing, the east coast will see only the rising rates before the peak. The further west you are in the US and Canada and westward across the International Date Line, the better your opportunity to capture the peak will be. It would be expected between 1300 and 1700 UT on January 3rd. That is 8 AM to Noon EST, and 5 AM to 9 AM PST. You can therefore see why the further west the better your location will be. The sun rises between 7 and 7:30 AM in North America and the moon sets around midnight, so there are a few dark hours to collect some good counts. I should point out that data on this shower is rather sparse, so a peak a few hours either side of these times is certainly possible.
IMO Video data has indicated a longer period of activity than in the official working list. Before January 1st and after the 5th, extreme care should be used in assigning meteors to this shower even though I list the positions below. These are moderately fast meteors with a velocity of 41 km/sec. 
It was suspected that the parent object of this shower was comet 96P/Machholz 1, but recent investigations by Jenniskens, Vaubaillon, Marsden and others has pointed the fickle finger of origin on another object, asteroid 2003 EH1. Since the particular orbit of the asteroid, the comet, and the meteoroids quickly evolve (nutate) it is quite possible all of them are related. The current inclination of the meteor stream, for example, of 72 degrees was 13 degrees only 1500 years ago. We are fortunate to be in the path of this stream at this time.
The radiant is named for a constellation that no longer exists; on today’s map of the sky it is in northern Bootes between Magnitude +3.5 Nekkar (the top of the “kite” of Bootes) and Draco’s sinuous body.
If the weather cooperates, bundle up and enjoy the show!
QUA (Quadrantids)-velocity 41 km/sec (medium)
00 UT Date, RA degrees (Hr:mm), Declination
Jan 01   229 (15:14), +50
Jan 03   230 (15:19), +49 (Peak)
Jan 05   231 (15:24), +49 (End of working list activity)
Jan 09   233 (15:34), +48 (Last morning with some moon free time)

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