Meteor Activity Outlook for November 9-15, 2007

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 but the sporadic rates are much lower than those seen in the northern
hemisphere.

During this period the moon reaches it new phase
on Friday November 9. At this time the moon will be located near the sun in the
sky and will not be visible during the nighttime hours. During the latter portion
of this period the moon will enter the evening sky as a waxing crescent but will
set well before the meteor rich morning hours arrive. The estimated total hourly rates for evening observers
this week is near four for those located in the mid-northern hemisphere (45 N) and
two for observers from the mid-southern hemisphere (45 S). For morning observers
the estimated total hourly rates should be near twenty for those located in the
mid-northern hemisphere (45 N) and ten for those viewing from the mid-southern
hemisphere (45 S). 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 and rates listed below are exact
for Saturday night/Sunday morning November 10/11. 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 between
November 8 and 15, peaking on the 9th. The position at maximum activity is 01:40
(025) +27. This position lies in northern Pisces, four degrees southwest of the
third magnitude star Alpha Trianguli. Visual activity is expected to be low, but
detectable. This radiant is close to the old time Andromedid radiant and one could
wonder if the two radiants are related. The radiant is best placed near 2200 (10pm)
local standard time. At 20km/sec., the average November Piscid 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.

The Northern Taurid (NTA) radiant is now centered at 03:44 (056) +22. This
position lies in western Taurus, two degrees south of the famous naked eye star
cluster known as the Pleiades or Seven Sisters. The Southern Taurid (STA)
radiant lies at 03:44 (056) +15. This position lies nine degrees south of the
Pleiades. The two radiants are separated by seven 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. At 29 and 27 km/sec., the average Taurid
meteor travels slowly through the skies.

The Leonids (LEO) are just now coming to life from a radiant located at
09:48 (147) +24. This position lies in western Leo, very close to the position of
the third magnitude star Epsilon Leonis. Maximum activity is predicted to occur on
November 18 so current rates would most likely be less than one per hour. Recent
studies of video data by Sirko Molau has indicated that the Leonids are active
longer than expected, with ZHR’s of at least one through November 28. At 70km/sec.,
the average Leo is swift with a high percentage of trains.

Sporadic rates have reached maximum for observers in the northern
hemisphere and are now slowly rising for those located south of the equator. One
would expect to see approximately sixteen random meteors during the last hour before
dawn from rural observing sites in the mid-northern hemisphere (45 N). During the
first dark hour after the end of evening twilight, perhaps four random meteors can
be seen per hour. As seen from the mid-southern hemisphere (45 S) late morning rates
would now be near six per hour. During the first dark hour after the end of evening
twilight, perhaps two random meteors can be seen per hour.