(meteorobs) Meteor Activity Outlook for January 9-15, 2010

[Robert Lunsford]

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 Friday January 15th. On that date the moon lies near the sun in the sky and is
not visible at night. This weekend the waning crescent moon rises during the early morning hours but should not cause any problems
if the observer keeps it out of their field of view. The estimated total hourly rates for evening observers this week is near three
no matter your location. For morning observers the estimated total hourly rates should be near eighteen from the northern hemisphere
and sixteen as seen from the southern hemisphere. 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 9/10. 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 wide Antihelion (ANT) radiant is now centered at 08:04 (122) +19. This area of the sky lies in western Cancer, three degrees
northwest of the faint star Zeta Cancri. This radiant is best placed near 0100 local standard time (LST) when it lies on the
meridian and is located highest in the sky. Due to the large size of this radiant, any meteor radiating from eastern Gemini, Canis
Minor, or Cancer could be a candidate for this shower. Rates at this time should be near three per hour as seen from the northern
hemisphere and two 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.

Studies of the IMO's video database by Sirko Molau has shown a radiant active in Cancer this time of year. This radiant is different
from the nearby Antihelion source but the meteors have essentially the same entry velocity. Activity from the Southern Delta
Cancrids (SCC) begin to appear on January 14th and peak four nights later. On the 14th the radiant is located at 08:20 (125) +07.
This position lies in southern Cancer, three degrees south of the fourth magnitude star Beta Cancri. These meteors are best seen
near 0100 LST when the radiant lies highest above the horizon. Hourly rates from this shower will be less than one per hour no
matter your location. At 29km/sec. the Southern Delta Cancrids produce meteors of medium-slow velocity.

The December Leonis Minorids (DLM) are active from a radiant located at 11:58 (180) +21. This position lies on the border of Leo and
Coma Berenices, six degrees northeast of the second magnitude star Denebola (Beta Leonis). These meteors are best seen near 0500 LST
when the radiant lies highest above the horizon. This shower peaked on December 20th so current rates would be near one per hour as
seen from the northern hemisphere and less than one per hour as seen from south of the equator. At 64km/sec. the December Leonis
Minorids produce mostly swift meteors.

The last of the Quadrantids (QUA) will be seen this weekend from a radiant located at 15:36 (234) +49. This position lies in a
remote area of northeastern Bootes. The nearest named star is the 4th magnitude Iota Draconis, which lies ten degrees to the north.
These meteors are best seen during the last dark hour of the night when the radiant lies highest above the horizon in a dark sky.
This shower peaked on January 3rd so current rates would be less than one per hour regardless of your location. At 42km/sec. the
Quadrantids produce mostly medium velocity meteors.

Another shower found by Sirko is the Xi Corona Borealids (XCB). This radiant is active from January 10th through the 15th with
maximum activity occurring on the 15th. The radiant is currently located at 16:36 (249) +30. This position lies in western Hercules,
three degrees southwest of the fourth magnitude star Zeta Herculis. These meteors are best seen during the last dark hour of the
night when the radiant lies highest above the horizon in a dark sky. Hourly rates are expected to be less than one regardless of
your location. At 50 km/sec. the Xi Corona Borealids produce mostly medium velocity meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately fourteen Sporadic meteors per hour during the
last hour before dawn as seen from rural observing sites. Evening rates would be near two per hour. As seen from the mid-southern
hemisphere (45S), morning rates would also be near fourteen per hour as seen from rural observing sites and two per hour during the
evening hours. Locations between these two extremes would see activity between the listed figures.

The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday
night/Sunday morning.

Antihelion (ANT)) - 08:04 (122) +19   Velocity - 30km/sec.
Northern Hemisphere - 3 per hr. Southern Hemisphere - 2 per hr.

Southern Delta Cancrids (SCC) - 08:20 (125) +07   Velocity - 29km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

December Leonis Minorids (DLM) - 11:58 (180) +21   Velocity - 64km/sec.
Northern Hemisphere - 1 per hr. Southern Hemisphere - <1 per hr.

Quadrantids (QUA) - 15:36 (234) +49   Velocity - 42km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Xi Corona Borealids (XCB) - 16:36 (249) +30   Velocity - 50km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

*For a detailed explanation on the different classes of meteor showers and other astronomical terms, please visit:
http://www.amsmeteors.org/showers.html#X2009

Clear Skies!
Robert Lunsford
American Meteor Society