(meteorobs) Meteor Activity Outlook for August 24-30, 2007

[Robert Lunsford]

August is the best month for viewing meteor activity from the northern
hemisphere. Not only is the activity enjoyable but the balmy nights are much
more pleasant than those experienced later in the year. As the month begins
the southern radiants are still active and often matching the sporadic
rates. The sporadic rates increase as the month progresses providing a
decent show for the normally slow evening hours. The Perseids kick into high
gear the second week of the month and fill the skies with colorful streaks
of light during the entire night. From the southern hemisphere activity
falls precipitously. This is much like what the northern hemisphere
experiences moving from January into February. The southern radiants put on
a good show the first week of the month. They taper off the second week and
are nearly extinct by the third. In the meantime the sporadic rates that
were so impressive in early July are now half as strong and still getting
weaker. Unless you are located near the equator you will not see much of the
Perseids. From the southern hemisphere any evening Perseids are impossible
to see. You have to wait until the last hours before dawn and hope that some
will shoot upwards from low in the northern sky.

During this period the moon reaches its full phase on Tuesday August 28. The
moon will remain a major factor during this entire period obscuring all but
the brightest meteors. The sources of meteors listed below are active during
this period but will be difficult to observe this week due to the lunar
glare. If your sky is transparent and the limiting magnitude exceeds +5.0,
then you may be able to achieve some success. The estimated total hourly
rates for evening observers this week is two from the northern hemisphere
and one from south of the equator. For morning observers the estimated
total hourly rates should be near seven from the northern hemisphere and
four from the southern hemisphere. 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. Rates are reduced this week due to intense moonlight.

The radiant positions listed below are exact for Saturday night/Sunday
morning August 25/26. 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. Taking this advice this 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 full descriptions of each active meteor shower will continue next week
when the moon becomes less of a nuisance to observers.

Antihelion (ANT) - 22:20 (335) -05
Northern Hemisphere - 1   Southern Hemisphere  -1

Epsilon Cassiopeiids (ECA)  02:20 (035) +62
Northern Hemisphere - <1   Southern Hemisphere  -<1

 Alpha Aurigids (AUR)  05:08 (077) +42
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