Meteor Activity Outlook for January 9-15, 2010

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.