The first week of January yields the first major meteor shower of the year, the famous but sometimes illusive Quadrantids. Like other meteor showers, the Quadrantids are named after the constellation (or nearby star) where the radiant is located, but you may have difficulty figuring out the associated region; the reason is that the constellation no longer exists!
Today, the Quadrantids radiant is located in the northern constellation of Boötes, not far from the tail of Ursa Major. When the shower was discovered by Adolphe Quetelet of the Brussels Observatory in the 1830s, the radiant was located in the now obsolete constellation of Quadrans Muralis, hence the name 'The Quadrantids'.
Quadrans Muralis was originally created by Joseph Jerome de Lalande in 1795. This constellation represents the mural quadrant, a wall mounted astronomical instrument Lalande used for measuring star positions. Although not defined as one of the 88 modern constellations by the International Astronomical Union (IAU), Quadrans Muralis is one of the more widely known obsolete constellations due to its association with the meteor shower.
Peak Activity and Observing
The Quadrantids are active for about 2 weeks starting at the end of December but are notorious for their short window of peak activity, lasting only about 6 hours. In 2012, the shower is expected to peak at about 07:25 UT on the 4th January with a Zenithal Hourly Rate (ZHR) of 120, one of the highest rates of all known periodical meteor showers.
For this year’s event, observers located in North America are favoured with local peaks ranging from 2:25am EST (4th January) for meteor watchers on the east coast to 11:25 PST (3rd January) for those on the west coast. In particular, observers on the eastern side of the continent are favoured as the radiant will be high in the sky at the time of maximum activity and the waxing gibbous Moon (77% illuminated) will be about to set.
However if the Moon is above the horizon from your location, all is not lost. A good tip is to stand with the Moon behind you and then look skywards, allowing yourself the darkest possible sky to view the meteor shower. As with all meteor showers the meteor trails often streak across the sky quite a distance from the actual radiant point, in many cases thirty, forty or more degrees away. They therefore can effectively appear anywhere in the sky.
The Quadrantids are best seen from the northern hemisphere. The radiant is circumpolar for locations north of latitude 41N and only briefly sets for mid-northern latitudes.
It is now believed that this shower is related to the recently discovered asteroid 2003 EH1. Along with the Geminids, the Quadrantids are the only major meteor showers not originating from a comet.
Quadrantids Data Table
|Meteor shower name||Quadrantids|
|Dates||28th December -> 12th January|
|Peak Date||4th January|
|RA (J2000)||15hr 20m|
|Parent||2003 EH1 (asteroid)|