A meteor shower active between January 1 and 6, but with marked activity confined mainly to a 12-hour interval around January 3/4. At maximum, the radiant lies at RA 15h 20m, dec. +49°, a few degrees northwest of Tau, Phi, and Nu Herculis in what used to be the constellation of Quadrans Muralis. The ZHR at maximum can be as high as 120, placing the Quadrantids among the three most active regular annual showers. Quadrantid meteors are moderately fast, with a geocentric velocity of 41 km/s. The stream orbit oscillates up and down relative to the ecliptic over the centuries. As a result, the stream will fail to encounter the Earth after about ad 2200. Attempts to identify a parent body are also confounded by this rapid motion of the orbit, although a strong connection with minor planet 2003 EH1 has been suggested. This object may be the remaining fragment of a comet that broke up a few hundred years before 1600, possibly Comet 1490 Y1. The Quadrantids may be an end member of a complex that includes the Delta Aquarid meteors, the Kracht and Marsden group comets, the daytime Arietid meteors, and Comet 96P/Machholz.
Subjects: Astronomy and Astrophysics.