(meteorobs) Meteor Activity Outlook for November 9-15, 2007

[Robert Lunsford]

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.

 November Piscids (NVP)  01:40 (025) +27
Northern Hemisphere - 1   Southern Hemisphere - <1

Northern Taurid (NTA)  03:44 (056) +22
Northern Hemisphere - 2   Southern Hemisphere - 1

Southern Taurid (STA)  03:44 (056) +15
Northern Hemisphere - 2   Southern Hemisphere - 1

Leonids (LEO)  09:48 (147) +24
Northern Hemisphere - <1   Southern Hemisphere - <1

*For a detailed explanation on the different classes of meteor showers and
other astronomical terms, please visit:
http://www.amsmeteors.org/showers.html#2007

Clear Skies!
Robert Lunsford
American Meteor Society