||2008 Quadrantid Shower|
The annual Quadrantid meteor shower occurs when debris from an asteroid or comet intercepts the Earth at a high velocity (41 km/s, 92,000 mph). The parent body of the stream isn't known with certainty, but has recently been proposed to be the minor planet 2003 EH1, which is itself probably a burned out comet. Meteor showers are named for the constellation of their radiant. The Quadrantids are unusual in being named for Quadrans Muralis, a constellation name that is no longer in use. This shower is sometimes called the Boötids because the radiant is found in the constellation Boötes.
This is a composite image of 46 meteors recorded between sunset on January 3 and sunrise on January 4. Since the images were collected over many hours, the radiant of the shower is not in a fixed location. During this time of year sporadic meteor activity is high as well. The Cloudbait allsky camera caught a total of 68 meteors on this particular evening - 46 Quadrantids and 22 sporadics. Mouse over the image to see all the meteors.
Meteors in this image range in brightness from about magnitude 1 (dimmest) to magnitude -7 (brightest). Meteors brighter than magnitude -4 are considered fireballs, and there are many captured here.
Long string-like images are stars or planets captured as they traveled across the sky over many hours.
This chart plots the total meteor activity over the evening of January 3/4. The radiant rose in Colorado at about UT 05:00, but the skies were somewhat cloudy for several hours. I don't know if the drop in activity at about 11:00 represents a true decrease in meteors, or if some cloudy conditions returned. The three curves shown here are the zenithal hourly rates obtained by the NASA MAC mission, the visual ZHR reported to the International Meteor Organization, and the computed ZHR obtained by the Cloudbait camera. The combined data shows an apparent true peak of activity at about UT 08:00, but an overall broad peak of sustained activity. At the Cloudbait site, astronomical twilight began at UT 12:45, extending to dawn at UT 14:20.
|This all sky radiant
map clearly shows the radiant concentration around the nominal RA= 230°,
dec=+49° (measured apparent radiant RA=231 ± 7°, dec=48 ±
3°). The shower's antiradiant is also apparent, and is seen because
meteors that occur when the radiant is low may appear to originate on the
opposite side of the sky.