Quadrantids 1998: Prospects
January 3, 21 UT (Marco Langbroek)


The Quadrantids are a major stream that, together with the Geminids, features the strongest activity of all annual streams. The peak is extremely sharp and lasts less than a day. It is superimposed on a shallow, low-level background activity stretching over a few days. Peak rates are in the order of ZHR ~130 (!). Perhaps, rates are slightly variable from year to year. That is also suggested for the average brightness of the meteors in this stream. The meteors during the narrow main peak are significantly brighter than those from the background extending over several days. The main peak is so steep that only a few hours after maximum rates have already significantly declined, and thus considerable rate variation is to be experienced over one observational night around maximum. The radiant culminates very low in the nortehern sky (or even below the horizon south of 40 degrees latitude North) around 20-21h local time and the steeply rises. Near the end of the night, it reaches very high altitudes in the northern hemisphere. This, combined with the steep rate profile, makes it very important when (in local time) the maximum will occur, regarding rates that can be seen. Maximum early in the evening means little meteors both early and later in the night.

This year, maximum occurs around 21h UT on January 3. Thus, Asian residents will have a favourable look on the maximum with the radiant high in the sky, but European observers will see the maximum occur while the radiant is at its lowest in the northern sky. By the time it reaches higher in the sky later that night, activity will have dropped noticably already, and near the end of the night the ZHR might have dropped already to values near ~40. USA observers will see only low rates. Still, the stream needs scrutiny from these areas too since much is still uncertain about its activity profile.

Recent Dutch photographic and video orbits suggest that the core of the stream is very young, no more than ~500 years old.



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DMS homepage		 back.gif This page was last modified on December 18, 1997 by
Casper ter Kuile and Marco Langbroek