Meteor Activity Outlook for November 1-7, 2008

As seen from the northern hemisphere, meteor
rates continue to be strong in November. While no major showers are active this
month, the two Taurid radiants plus the Leonids keep the skies active. The
addition of strong sporadic rates make November one of the better months to view
meteor activity from north of the equator. Skies are fairly quiet as seen from
the southern hemisphere this month. Activity from the three showers mentioned
above may be seen from south of the equator, but the sporadic rates are much
lower than those seen in the northern hemisphere.

During this period the moon reaches its first
quarter phase on Thursday November 6th. At this time the moon will be located
ninety degrees east of the sun and will set near midnight local standard time.
This weekend the waxing crescent moon will set during the early evening and not
interfere with observing. The estimated total hourly rates for evening observers
this week is near five for those located in the mid-northern hemisphere (45 N)
and two for those viewing from the mid-southern hemisphere (45 S). For morning
observers the estimated total hourly rates should be near twenty four for those located
in the mid-northern hemisphere (45 N) and twelve 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 moonlight.

The radiant positions and rates listed below are exact
for Saturday night/Sunday morning November 1/2. 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:

Sirko Molau’s studies of video radiants has revealed activity in Pisces and then
into Andromeda between November 1st and the 19th, peaking on the 5th. The position
at maximum activity is 01:32 (023) +30. This position lies on the Pisces-Triangulum
border, four degrees west of the third magnitude star Alpha Trianguli. Visual activity
is expected to be low, but detectable. The Andromedid radiant is best placed
near 2200 (10pm) local standard time. At 20km/sec., the average Andromedid will appear
as a very slow moving meteor. Sirko mentions that these meteors are “conspicuously
slow and of almost constant activity” during this period.

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 center of the large Northern Taurid (NTA) radiant is now centered at
03:16 (049) +20. This position lies in eastern Aries near the fourth magnitude
star Delta Arietis. The center of the large Southern Taurid (STA) radiant
lies at 03:16 (049) +14. This position also lies in eastern Aries, six degrees
south 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 less difficult to distinguish those meteors traveling east or west. These
radiants are best placed near the meridian at 0200 local daylight time (LDT). At
29 and 27 km/sec., the average Taurid meteor travels slowly through the skies.

Sirko Molau’s new studies of video radiants has revealed that the Northern Taurid’s
reach two plateaus of activity with the first occurring on October 20th. The
moon subdued this activity so it was most likely not noticed. The secondary peak is
predicted to occur near November 13th and will be severely hampered by a bright
moon. The same study has revealed that the Southern Taurids may have peaked near
October 11 and that the activity for this shower will remain fairly constant through
the first week of November. After that rates will dwindle until these meteors disappear
near the end of November.

The Orionids (ORI) peaked on the morning of October 21st. Rates will now
dwindle until the shower is no longer detectable. The radiant is now located at
06:48 (102) +16. This position lies in southwestern Gemini, two degrees east of
the second magnitude star Alhena (Gamma Geminorum). The radiant rises near 2300 LDT
and is best placed on the meridian near 0500. At 66km/sec., the average Orionid is
swift.

Sirko Molau’s studies of video radiants has revealed activity in northern
Cancer between October 10 and November 4, peaking on the October 14th. The radiant
for the Iota Cancrids (ICA) lies at 09:36 (144) +29. This position lies in
northwestern Leo, five degrees northwest of the fourth magnitude star Upsilon
Leonis. Visual activity is expected to be low, especially since we are now two weeks
past the peak. The radiant rises near 0200 LDT and is best placed high in the east
during the last dark hour of the morning. At 67km/sec., the average Iota Cancrid
will appear move swiftly through the skies.

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

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.