Meteor Activity Outlook for January 4-10, 2008

January sees a peak of sporadic activity for the southern hemisphere while rates seen north of the equator begin a steady downward turn that continues throughout the first half of the year. The sporadic activity is good for both hemispheres, but not as good as it was for northern observers in December. Once the Quadrantids have passed the shower activity for January is very quiet.

During this period the moon reaches its new phase on Tuesday January 8. At this time the moon will be located close to the sun and will not be visible at night. The estimated total hourly rates for evening observers this week is near two no matter your location. For morning observers the estimated total hourly rates should be near twenty for those located in the mid-northern hemisphere (45 N) and sixteen for those viewing from the mid-southern hemisphere (45 S). These rates assume that you are watching from rural areas away from all sources of light pollution. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning January 5/6. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.

The following showers are expected to be active this week:

The wide Antihelion (ANT) radiant is now centered at 07:52 (118) +20. This area of the sky lies in eastern Gemini, eight degrees south of the first magnitude star Pollux (Beta Geminorum). This radiant is best placed near 0100 local standard time when it lies on the meridian and is highest in the sky. Actually any meteor from eastern Gemini or western Cancer could be a candidate for this shower. Rates at this time should be near two per hour as seen from the northern hemisphere and one per hour for observers located south of the equator. With an entry velocity of 30 km/sec., the average Antihelion meteor would be of medium-slow speed.

Sirko Molau's study of video radiants has revealed activity during the period January 3-9, from an area in western Hydra. Maximum occurs on January 4 with the radiant located at 08:32 (128) -13. This position lies fifteen degrees southwest of the second magnitude star Alpha Hydrae. This radiant is best placed near 0200 LST when it lies on the meridian and is highest in the sky. Rates are most likely less than one shower member per hour no matter your observing location. At 39km/sec., the average meteor from this radiant would be of average velocity.

Sirko Molau's study of video radiants has also revealed activity during the period January 1-6, from an area in western Leo. Maximum occurs on January 3 with the radiant located at 09:44 (146) +25. This position lies very close to the third magnitude star Epsilon Leonis. This radiant is best placed near 0300 LST when it lies on the meridian and is highest in the sky. Rates are most likely less than one shower member per hour no matter your observing location. At 55km/sec., the average meteor from this radiant would be swift.

The Coma Berenicids (COM) are active from a radiant located at 12:40 (190) +18. This area of the sky is located in a remote area of central Coma Berenices. The nearest bright star is Denebola (Beta Leonis), located some fifteen degrees to the southwest. Current rates would be near one shower member per hour. These meteors are best seen near 0600 local standard time when the radiant lies highest above the horizon. At 65 km/sec. the Coma Berenicids will usually produce meteors of swift velocity.

The Quadrantids (QUA) reach maximum activity near 0640 UT on January 4. This timing is good for the Northern Atlantic region including extreme western Europe and eastern North America. The exact maximum is difficult to catch under perfect conditions where the shower peaks with the radiant located high in the sky. Most observers will do well seeing rates of fifty Quadrantids per hour. Most of Europe and North America will see maximum rates of less than fifty per hour. From high northern latitudes some Quadrantid activity may be seen during the evening hours. A few Quadrantids may be seen from the equator and low southern latitudes during the small window of time between the rise of the radiant and the start of morning twilight. At higher southern latitudes the radiant does not rise until the sky is too bright so no Quadrantid activity is visible south of approximately 30 degrees south latitude. On January 4th the radiant is located at 15:20 (230) +49. This area of the sky is located in an empty portion of northeastern Bootes some twenty degrees east of the second magnitude star Alkaid (Eta Ursae Majoris). The nearest bright star is third magnitude Beta Bootis, lying eight degrees to the southwest of the Quadrantid radiant. On the morning of January 5, the rates have dropped back below the sporadic background. The ZHR is back down to one on January 6 and all traces of the shower disappear by January 13. At 41 km/sec. the Quadrantids produce meteors of average to swift velocity. This shower is also known as the Bootids.

Sporadic rates are now slowly falling for observers in the northern hemisphere and rising for those located south of the equator. One would expect to see approximately fourteen random meteors during the last hour before dawn from rural observing sites no matter your geographic location. During the first dark hour after the end of evening twilight, perhaps two random meteors can be seen per hour.

The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning. Note that the Quadrantid rates have fallen to near nothing after peaking only two days prior.