(meteorobs) Meteor Activity Outlook for November 28-December 4, 2009

[Robert Lunsford]

No matter where you live, the first half of December provides some of the best meteor activity of the year. In the northern
hemisphere the sporadic rates are still strong plus you can also count on strong activity from the Geminids, which peak on December
13. There are also several minor radiants that add a few meteors each hour. All of these centers of activity are located high in the
sky during the early morning hours this time of year. Unfortunately this year the bright moon spoils the show during the first week
of the month. During the second week of December the moon will pass its last quarter phase and will not be such a nuisance .

As seen from the southern hemisphere the sporadic rates are increasing toward a January maximum. Shower rates are also good but the
Geminids suffer a bit from the lower elevation seen from southern locations. Still with the warmer weather now occurring south of
the equator, December is a great time to view celestial fireworks.

During this period the moon reaches its full phase on Wednesday December 2nd. On that date the moon lies opposite the sun and rises
near sunset and sets near sunrise. This weekend the waxing gibbous moon will set a few hours before dawn, allowing a brief chance at
observing under pristine conditions before morning twilight. The estimated total hourly rates for evening observers this week is
near three as seen from the northern hemisphere and two from the southern hemisphere. For morning observers the estimated total
hourly rates should be near fifteen from the northern hemisphere and twelve as seen from the southern hemisphere. 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. Rates are reduced during this period due to moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning November 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. 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 Phoenicids (PHO) are a periodic shower that rarely produces noticeable activity. The only impressive display produced by this
shower occurred in 1956 when ZHR's were near 100. Peak activity occurs on December 6. Little activity is expected away from the peak
night. The radiant is currently located at 00:48 (012) -52. This position lies in southeastern Phoenix some five degrees northwest
of the bright zero magnitude star Achernar (Alpha Eridani). These meteors are best seen near 2000 (8pm) local standard time (LST,
regardless of time zone) when the radiant lies highest above the horizon in a dark sky. Due to the southerly declination of the
radiant, this shower is not visible north of the northern tropical areas. The deep southern hemisphere has the best chance of seeing
any activity. At 18 km/sec. the Phoenicids produce very slow meteors.

Sirko Molau's studies of video radiants has revealed that activity from the famous Andromedid (AND) shower, noted for intense storms
during the 19th century, may still be seen throughout November. The current position of the large radiant is 01:44 (026) +45. This
position lies in northeastern Andromeda, five degrees northwest of second magnitude Almach (Gamma Andromedae). Visual activity is
expected to be low, but detectable. The Andromedid radiant is best placed near 2100 (9pm) local standard time (LST) when it lies on
the meridian and overhead for observers viewing from mid-northern latitudes . At 19km/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.

The Northern Taurids (NTA) are active from a large radiant centered at 04:52 (073) +25, which lies in eastern Taurus, eight degrees
northeast of the orange first magnitude star Aldebaran (Alpha Tauri). The radiant is best placed near 0000 (midnight) LST, when it
lies highest above the horizon, but activity may be seen all night long. Meteors from the Northern Taurids strike the atmosphere at
29km/sec., which would produce meteors of slow velocity. Expected rates would be near two per hour as seen from the northern
hemisphere and one per hour as seen south of the equator.

The November Orionids (NOO) were recently discovered Sirko Molau by analyzing video data. This shower is active from November 12
through December 6. Maximum activity occurs on November 30 when rates should be near one per hour, no matter your observing
location. The radiant is currently located at 06:04 (091) +15. This position lies in northeastern Orion, just west of the fourth
magnitude star Nu Orionis. These meteors are best seen near 0130 LST when the radiant lies on the meridian and highest above the
horizon. At 44 km/sec. the November Orionids produce mostly medium velocity meteors.

The Sigma Hydrids (HYD) are active from a radiant located at 07:52 (118) +04. This position lies in eastern Canis Minor, three
degrees southeast of the zero magnitude star Procyon (Alpha Canis Minoris). These meteors are best seen near 0300 LST when the
radiant lies highest above the horizon in a dark sky. Current rates would be less than one per hour no matter your location. At 61
km/sec. the Sigma Hydrids produce mostly swift meteors.

The Puppid-Velids (PUP) are a vast complex of weak radiants located in the constellations of Puppis and Vela. Visual plots and
photographic studies have revealed many radiants in this area during November and December. The combined strength of these radiants
can produce a ZHR of ten. Actual hourly rates will be much less unless you happen to be observing from the deep Southern Hemisphere.
The center of this activity is currently located at 07:52 (118) -45. This position lies in eastern Puppis, four degrees northwest of
the second magnitude star Gamma Velorum. Peak rates occur near December 7. These meteors are best seen near 0300 LST when the
radiant lies highest above the horizon in a dark sky. Observers located in the Southern Hemisphere have an advantage viewing this
shower as the radiant will rise higher into their sky allowing more activity to be seen. At 40 km/sec. the Puppid-Velids produce
meteors of average velocity.

The Leonids (LEO) reached maximum activity on the morning of November 17th with ZHR's exceeding 100 as seen over Asia. The last
chance to see Leonid activity in 2009 is this weekend when the radiant lies at 10:44 (161) +14. This position lies in central Leo,
seven degrees southeast of the famous second magnitude double star Algeiba (Gamma Leonis). Current rates would be less than one per
hour no matter your location. At 70km/sec., the average Leonid is swift with a high percentage of trains. The radiant is most
favorably located during the last dark hour before the onset of morning twilight when it lies highest in a dark sky.

Some observers have been reporting activity from Ursa Major while viewing the Geminids. Video studies by Sirko Molau have revealed a
radiant active in this constellation from November 29th through December 13th. Peak rates occur near December 5th. The radiant of
the Psi Ursa Majorids (PSU) is currently located at 10:36 (159) +45. This position actually lies in Leo Minor, very close to the
position occupied by the third magnitude star Beta Leonis Minoris. These meteors are best seen during the last hour before dawn when
the radiant lies highest in a dark sky. Current rates would be less than one per hour no matter your location. Due to the high
northern declination these meteors are best seen from the northern hemisphere. They are completely invisible south of 45 degrees
south latitude. At 61 km/sec. the Psi Ursa Majorids produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately twelve 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 six 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. Rates are reduced during this period due
to the intense moonlight.

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

Phoenicids (PHO)  - 00:48 (012) -52   Velocity - 18km/sec.
Northern Hemisphere -<1 per hr. Southern Hemisphere - <1 per hr.

Andromedids (AND)  - 01:44 (026) +45   Velocity - 19km/sec.
Northern Hemisphere -<1 per hr. Southern Hemisphere - <1 per hr.

Northern Taurids (NTA)  - 04:52 (073) +25    Velocity - 29km/sec.
Northern Hemisphere - 2 per hr. Southern Hemisphere - 1 per hr.

November Orionids (NOO) - 06:04 (091) +15    Velocity - 44km/sec.
Northern Hemisphere - 1 per hr. Southern Hemisphere - 1 per hr.

Sigma Hydrids (HYD)  - 07:52 (118) +04   Velocity - 61km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Puppid-Velids (PUP)  - 07:52 (118) -45   Velocity - 40km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Psi Ursa Majorids (PSU)  - 10:36 (159) +45    Velocity - 61km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

Leonids (LEO)  - 10:44 (161) +14    Velocity - 70km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr.

*For a detailed explanation on the different classes of meteor showers and other astronomical terms, please visit:
http://www.amsmeteors.org/showers.html#X2009

Clear Skies!
Robert Lunsford
American Meteor Society