(meteorobs) Meteor Activity Outlook for August 18-24, 2006

[Robert Lunsford]

During August observers in the northern hemisphere continue to see a rise in
the meteor activity, especially near August 12, when the Perseids reach
maximum strength. This peak is somewhat modified this year by the bright
gibbous moon that will be present during the Perseid maximum. Observers
south of the equator are seeing their rates plummet as the Perseids have
little effect in producing activity from the far southern latitudes.

This week the moon will reach its new phase on Wednesday August 23rd. This
weekend the waning crescent moon will rise during the early morning hours,
but will not be too bothersome. As the week progresses, the moon will
disappear into the sun's glare leaving the entire night free of interfering
moonlight. The estimated total hourly rates for evening observers this week
is near three for those north of the equator and two for those south of the
equator. For morning observers the estimated total hourly rates should be
near twenty for those in the northern hemisphere and twelve 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 August 19/20. 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.

The Kappa Cygnids (KCG) peak on August 17 with a ZHR or 3. They are active
from a wide radiant located at 19:04 (286) +59. This position is located in
southern Draco, five degrees northwest of the fourth magnitude star Kappa
Cygni. Current rates would be near 2 shower members per hour as seen from
the northern hemisphere. Due to the high northern declination (celestial
latitude) this shower is poorly seen from the southern hemisphere. A large
percentage of these meteors are bright, often fireball class meteors with
brilliant colors. With an entry velocity of 25 km/sec. most of these meteors
will appear to travel slower than average. The radiant is best placed near
2300 Local Daylight Time (11pm LDT your local time) when it lies nearly
overhead for much of the northern hemisphere.

The Antihelion (ANT) radiant is now centered at 22:40 (340) -07. This area
of the sky is centered in central Aquarius, eight degrees north of the third
magnitude star Delta Aquarii. This radiant is best placed near 0200 local
daylight time when it lies on the meridian and is highest in the sky. Rates
at this time should be near two per hour regardless of your location. With
an entry velocity of 30 km/sec., the average Antihelion meteor would be of
medium-slow speed.

The Southern Delta Aquarids (SDA) are near the end of their activity period.
Current rates would be less than 1 per hour regardless of your location. The
radiant is currently located at 23:44 (356) -11. This position lies in
eastern Aquarius, four=] degrees north of the fourth magnitude star Omega2
Aquarii. The radiant is best placed near 0300 local daylight time, when it
lies highest in the sky. Observers near 20 degrees south latitude are most
favored with longer nights and the radiant passing through the zenith. With
an entry velocity of 41 km/sec., most activity from this radiant would be of
average velocities.

Perseid (PER) activity is now near two per hour, as seen from the northern
hemisphere. The shower is practically invisible for observers south of the
equator. The current radiant position lies at 03:48 (057) +58, which is
located in southwestern Camelopardalis, nine degrees northeast of the second
magnitude star Mirfak (Alpha Persei). The radiant is well placed for those
in the northern hemisphere during the last few hours before dawn. At 59
km/sec., Perseid meteors are swift, often exhibiting persistent trains.

Sporadic rates continue to climb for observers located in the northern
hemisphere. One would expect to see perhaps thirteen random meteors during
the last hour before dawn from rural observing sites. During the first dark
hour after the end of evening twilight, perhaps three random meteors can be
seen per hour. Sporadic rates increase as the night progresses so rates seen
near midnight would be near seven per hour. Sporadic rates seen from the
southern hemisphere are now falling rapidly. One would see approximately
eight 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 five per hour.

Kappa Cygnids (KCG) - 19:04 (286) +59
Northern Hemisphere 2 - Southern Hemisphere <1

Antihelion (ANT) - 22:40 (340) -07
Northern Hemisphere 2 - Southern Hemisphere 2

Southern Delta Aquarids (SDA) 23:44 (356) -11
Northern Hemisphere <1 - Southern Hemisphere <1

Perseids (PER) 03:48 (057) +58
Northern Hemisphere 2 - 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#X2006

Clear Skies!
Robert Lunsford
American Meteor Society