(meteorobs) Meteor Activity Outlook for January 3-9, 2009

Robert Lunsford lunro.imo.usa at cox.net
Fri Jan 2 12:08:25 EST 2009

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 it first quarter phase on Sunday January
4th. At this time the moon lies ninety degrees east of the sun and sets near
midnight. Next week the waxing gibbous moon sets later in the morning with
each passing night. This narrows the window of opportunity to view meteor
activity is a truly dark sky. 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 twenty five for
those located in the mid-northern hemisphere (45 N) and fifteen for those
viewing from the mid-southern hemisphere (45 S). Locations between these two
extremes would see activity between the listed figures. 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. Evening rates are reduced due to

The radiant positions and rates listed below are exact for Saturday
night/Sunday morning January 3/4. 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 07:44 (116) +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 (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 or western 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.

The Alpha Hydrids (AHY) are active from a radiant located at 08:24
(126) -09. This area of the sky is located in southwestern Hydra, fifteen
degrees west of the second magnitude star Alphard (Alpha Hydrae). These
meteors are best seen near 0300 LST when the radiant lies highest above the
horizon. Rates should currently be near one per hour no matter your
location. At 40 km/sec. the Alpha Hydrids will usually produce meteors of
medium velocity.

The Coma Berenicids (COM) are active from a radiant located at 11:40 (175)
+25. This area of the sky is located in northeastern Leo, ten degrees north
of the second magnitude star Denebola (Beta Leonis). These meteors are best
seen near 0500 LST when the radiant lies highest above the horizon. Rates
should currently be near two per hour as seen from the northern hemisphere
and one per hour as seen from locations south of the equator. At 64 km/sec.
the Coma Berenicids will usually produce meteors of swift velocity.

The Quadrantids (QUA) reach maximum activity near 1300 UT on January 3. This
timing is good for the west coast of 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. From high northern latitudes some Quadrantid
activity may be seen during the evening hours but during 2009 the moon will
be above the horizon 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. The first quarter moon will set near midnight allowing the more
active morning hours to be free of interfering moonlight. On January 3rd 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 4th, the rates will have
dropped back below the sporadic background. The ZHR is back down to one on
January 5th and all traces of the shower disappear by January 13. At 42
km/sec. the Quadrantids produce meteors of average to swift velocity. This
shower is also known as the Bootids.

As seen from the mid-northern hemisphere (45N) one would expect to see
approximately fifteen 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 be
near thirteen 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. Evening rates are reduced due to

The table below presents a summary of the expected activity this week. Rates
and positions are exact for Saturday night/Sunday morning but may be used
all week.

Antihelion (ANT) 07:44 (116) +20  Velocity - 30 km/sec.
Northern Hemisphere - 3   Southern Hemisphere - 2

Alpha Hydrids (AHY) 08:24 (126) -09 Velocity - 40 km/sec.
Northern Hemisphere - 1   Southern Hemisphere - 1

Coma Berenicids (COM)  11:40 (175) +25  Velocity - 64 km/sec.
Northern Hemisphere - 2   Southern Hemisphere - 1

Quadrantids (QUA)  15:20 (230) +49   Velocity - 42 km/sec.
Northern Hemisphere - 5   Southern Hemisphere - <1

*For a detailed explanation on the different classes of meteor showers and
other astronomical terms, please visit:

Clear Skies!
Robert Lunsford
American Meteor Society

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