(meteorobs) Meteor Activity Outlook for October 27 - November 2, 2006

[Robert Lunsford]

Meteor rates continue to be strong as seen from the northern hemisphere. The
antihelion radiant has now merged with the two Taurid radiants producing
slow meteors during the late evening and early morning hours. Meteors from
the Orionid radiant are visible most of the month. Strong sporadic rates
continue during the morning hours as long as the moon is below the horizon.
>From the southern hemisphere, sporadic rates have reached their nadir and
begin a slow recovery the second half of the month. Meteors from the Taurid
and Orionid radiants also help to fill the southern skies with more activity
than has been seen since July. A new moon during the peak of the Orionid
shower is a plus for all and should help inflate meteor totals that have
suffered since the Perseid maximum back in August.

This week the moon reaches its first quarter phase on Sunday October 29. At
this time the moon will set near midnight local standard time (LST) and will
not be a factor in observing during the busy morning hours. The estimated
total hourly rates for evening observers this week is near four for those
north of the equator and two for observers south of the equator. For morning
observers the estimated total hourly rates should be near thirty for
northern observers and twenty for those south of the equator. 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 listed below are exact for Saturday night/Sunday
morning October 28/29. 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. 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.

These showers are expected to be active this week:

At this time of year debris from comet 2P/Encke produces a double radiant
very close to the position of the antihelion radiant. From now through the
end of November, it is impossible to resolve the antihelion meteors from
those produced by comet 2P/Encke. Therefore we suggest that observers simply
classify meteors from this area as either north or south Taurids. Although
the radiants actually lie in Aries during October, they reach maximum
activity in November when they are situated in the constellation of Taurus.

The Northern Taurid (NTA) radiant is now centered at 03:04 (046) +20. This
position lies in eastern Aries, two degrees west of the fourth magnitude
star Delta Arietis. The Southern Taurid (STA) radiant lies at 03:04 (046)
+14. This position lies in southeastern Aries, five degrees southwest of
Delta Arietis. The two radiants are separated by slightly over five degrees.
Since they have the same right ascension (celestial longitude), it is
difficult to distinguish meteors that move north or south out of the
radiants. It is slightly less difficult to distinguish those meteors
traveling east or west.

These radiants are above the horizon most of the night and are best placed
near midnight LST, when they lie on the meridian and are located highest in
the sky. Rates at this time should be near three per hour for the southern
radiant and two per hour for the northern radiant, regardless of your
location. With an entry velocity near 30 km/sec., the average Taurid meteor
would be of medium-slow speed.

The Orionids (ORI) put on a fantastic display this past weekend. Rates were
three times than what were expected. Rates are still above normal at around
10-15 per hour. The radiant has now moved into the constellation of Gemini
and is located at 06:40 (100) +16. This position lies in southwestern
Gemini, at the spot occupied by the second magnitude star Alhena (Gamma
Geminorum). The radiant rises near 2100 LST and is best placed on the
meridian near 0400. Rates will slowly diminish as we move further away from
the date of maximum activity. At 64km/sec., the average Orionid is swift.

Sirko Molau's study of video radiants has revealed activity from the
Gemini/Cancer border during the period October 27 through November 4.
Maximum occurs on October 31 with a radiant located at 07:44 (121) +16. This
position lies in western Cancer, three degrees southwest of the faint star
known as Zeta Cancri. This radiant is best placed on the meridian near 0500
LST. It appears that six percent of the total activity for the night is
related to this radiant. At 60km/sec., the average meteor from this radiant
would be swift.

Sporadic rates have reached the late year plateau for observers located in
the northern hemisphere. One would expect to see perhaps sixteen random
meteors during the last hour before dawn from rural observing sites. During
the first dark hour after the end of evening twilight, perhaps four random
meteors can be seen per hour. Sporadic rates increase as the night
progresses so rates seen near midnight would be near ten per hour. Sporadic
rates seen from the southern hemisphere have passed their annual minimum and
are rising again. One would expect to see approximately five random meteors
per hour during the last hour before dawn and two per hour during the first
dark hour after the end of evening twilight. Rates near midnight would be
near four per hour.

Northern Taurid (NTA) 03:04 (046) +20
Northern Hemisphere - 2   Southern Hemisphere - 2

Southern Taurid (STA)  03:04 (046) +14
Northern Hemisphere - 3   Southern Hemisphere - 3

Orionids (ORI)  06:40 (100) +16
Northern Hemisphere - 10   Southern Hemisphere - 10
 Zeta Cancrids (ZCA)  07:44 (121) +16
Northern Hemisphere - 2   Southern Hemisphere - 2

*For a detailed explanation on the different classes of meteor showers and
other astronomical terms, please visit:
http://www.amsmeteors.org/showers.html#X2006

Clear Skies!
Robert Lunsford
American Meteor Society